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Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Ultrafast X-ray Absorption Spectroscopy using Laser-Driven Electron X-ray Sources (LEXS)  

E-Print Network [OSTI]

: ultrafast x-rays, x-ray absorption spectroscopy, terawatt lasers, ultrafast reaction dynamics, atomic motion atomic motion by scrutinizing the changes in x- ray absorption spectra during reactions. FirstUltrafast X-ray Absorption Spectroscopy using Laser-Driven Electron X-ray Sources (LEXS) Guangjun

Guo, Ting

2

Damage of supercoiled DNA by an ultrafast laser-driven electron x-ray source  

Science Journals Connector (OSTI)

Using magnetic fields to differentiate the effects of electrons and x-rays, it was discovered that single strand breaks in supercoiled DNA were

Shan, Fang; Carter, Joshua D; Guo, Ting

2007-01-01T23:59:59.000Z

3

A Hybrid Laser-driven E-beam Injector Using Photo-cathode Electron Gun and superconducting Cavity*  

E-Print Network [OSTI]

A Hybrid Laser-driven E-beam Injector Using Photo-cathode Electron Gun and superconducting Cavity, Beijing 100871, China * Work supported by NNSF of China Abstract A laser-driven photo-cathode electron gun constructed and tested. As the next step, a hybrid photo-injector, using a DC laser-driven electron gun

Geng, Rong-Li

4

Characterisation of electron beams from laser-driven particle accelerators  

SciTech Connect (OSTI)

The development, understanding and application of laser-driven particle accelerators require accurate measurements of the beam properties, in particular emittance, energy spread and bunch length. Here we report measurements and simulations showing that laser wakefield accelerators can produce beams of quality comparable to conventional linear accelerators.

Brunetti, E.; Manahan, G. G.; Shanks, R. P.; Islam, M. R.; Ersfeld, B.; Anania, M. P.; Cipiccia, S.; Issac, R. C.; Vieux, G.; Welsh, G. H.; Wiggins, S. M.; Jaroszynski, D. A. [Physics Department, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

2012-12-21T23:59:59.000Z

5

All-laser-driven, MeV-energy X-ray source for detection of SNM Sudeep Banerjee, Nathan Powers, Vidya Ramanathan, Nathaniel Cunningham, Nate Chandler-Smith, Shouyuan  

E-Print Network [OSTI]

All-laser-driven, MeV-energy X-ray source for detection of SNM Sudeep Banerjee, Nathan Powers, MI 48109. A quasi-monoenergetic MeV x-ray source based on laser-driven electron acceleration per laser shot. Characterization of such a high-flux high energy x-ray beam is in progress. Quasi

Umstadter, Donald

6

Physics of laser-driven plasma-based electron accelerators E. Esarey, C. B. Schroeder, and W. P. Leemans  

E-Print Network [OSTI]

Physics of laser-driven plasma-based electron accelerators E. Esarey, C. B. Schroeder, and W. P Laser-driven plasma-based accelerators, which are capable of supporting fields in excess of 100 GV/m, are reviewed. This includes the laser wakefield accelerator, the plasma beat wave accelerator, the self

Geddes, Cameron Guy Robinson

7

Quantitative X-Ray Phase-Contrast Microtomography from a Compact Laser Driven Betatron Source  

E-Print Network [OSTI]

X-ray phase-contrast imaging has recently led to a revolution in resolving power and tissue contrast in biomedical imaging, microscopy and materials science. The necessary high spatial coherence is currently provided by either large-scale synchrotron facilities with limited beamtime access or by microfocus X-ray tubes with rather limited flux. X-rays radiated by relativistic electrons driven by well-controlled high-power lasers offer a promising route to a proliferation of this powerful imaging technology. A laser-driven plasma wave accelerates and wiggles electrons, giving rise to brilliant keV X-ray emission. This so-called Betatron radiation is emitted in a collimated beam with excellent spatial coherence and remarkable spectral stability. Here we present the first phase-contrast micro-tomogram revealing quantitative electron density values of a biological sample using betatron X-rays, and a comprehensive source characterization. Our results suggest that laser-based X-ray technology offers the potential fo...

Wenz, J; Khrennikov, K; Bech, M; Thibault, P; Heigoldt, M; Pfeiffer, F; Karsch, S

2014-01-01T23:59:59.000Z

8

Characterization of a novel, short pulse laser-driven neutron source  

SciTech Connect (OSTI)

We present a full characterization of a short pulse laser-driven neutron source. Neutrons are produced by nuclear reactions of laser-driven ions deposited in a secondary target. The emission of neutrons is a superposition of an isotropic component into 4? and a forward directed, jet-like contribution, with energies ranging up to 80 MeV. A maximum flux of 4.4 × 10{sup 9} neutrons/sr has been observed and used for fast neutron radiography. On-shot characterization of the ion driver and neutron beam has been done with a variety of different diagnostics, including particle detectors, nuclear reaction, and time-of-flight methods. The results are of great value for future optimization of this novel technique and implementation in advanced applications.

Jung, D.; Falk, K.; Guler, N.; Devlin, M.; Favalli, A.; Fernandez, J. C.; Gautier, D. C.; Haight, R.; Hamilton, C. E.; Hegelich, B. M.; Johnson, R. P.; Merrill, F.; Schoenberg, K.; Shimada, T.; Taddeucci, T.; Tybo, J. L.; Wender, S. A.; Wilde, C. H.; Wurden, G. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Deppert, O. [Technische Universität Darmstadt, 64289 Darmstadt (Germany)] [Technische Universität Darmstadt, 64289 Darmstadt (Germany); and others

2013-05-15T23:59:59.000Z

9

CONCEPTUAL DESIGN OF A BRIGHT ELECTRON INJECTOR BASED ON A LASER-DRIVEN PHOTOCATHODE RF ELECTRON GUN  

SciTech Connect (OSTI)

Conceptual design of a bright electron injector for the 1 GeV high gradient test experiment. envisaged by the LLNL-SLAC-LBL collaboration on the Relativistic Klystron is presented. The design utilizes a high-brightness laser-driven RF photocathode electron gun, similar to the pioneering LANL early studies in concept (different parametrically however), together with achromatic magnetic bunching and transport systems and diagnostics. The design is performed with attention to possible use in an FEL as well. A simple but realistic analytic model including longitudinal and transverse space-charge and RF effects and extensive computer simulation form the basis of the parametric choice for the source. These parameters are used as guides for the design of the pico-second laser system and magnetic bunching section.

Chattopadhyay, S.; Chen, Y.J.; Hopkins, D.; Kim, K.J.; Kung, A.; Miller, R.; Sessler, a.; Young, T.

1988-09-01T23:59:59.000Z

10

Fast ignition of fusion targets by laser-driven electrons  

E-Print Network [OSTI]

We present hybrid PIC simulations of fast electron transport and energy deposition in pre-compressed fusion targets, taking full account of collective magnetic effects and the hydrodynamic response of the background plasma. Results on actual ignition of an imploded fast ignition configuration are shown accounting for the increased beam divergence found in recent experiments [J.S. Green et al., Phys. Rev. Lett. 100, 015003 (2008)] and the reduction of the electron kinetic energy due to profile steepening predicted by advanced PIC simulations [B. Chrisman et al. Phys. Plasmas 15, 056309 (2008)]. Target ignition is studied as a function of injected electron energy, distance of cone-tip to dense core, initial divergence and kinetic energy of the relativistic electron beam. We found that beam collimation reduces substantially the ignition energies of the cone-guided fuel configuration assumed here.

Honrubia, J J

2008-01-01T23:59:59.000Z

11

CONCEPTUAL DESIGN OF A BRIGHT ELECTRON INJECTOR BASED ON A LASER-DRIVEN PHOTOCATHODE RF ELECTRON GUN  

E-Print Network [OSTI]

feasibility of a Bright Electron Source that sati sfies theinvestigations on the Bright Electron Source. l'. \\III:-'TTinjected by (3) a bright electron source. We nre concerned

Chattopadhyay, S.

2010-01-01T23:59:59.000Z

12

Photonic laser-driven accelerator for GALAXIE  

SciTech Connect (OSTI)

We report on the design and development of an all-dielectric laser-driven accelerator to be used in the GALAXIE (GV-per-meter Acce Lerator And X-ray-source Integrated Experiment) project's compact free-electron laser. The approach of our working design is to construct eigenmodes, borrowing from the field of photonics, which yield the appropriate, highly demanding dynamics in a high-field, short wavelength accelerator. Topics discussed include transverse focusing, power coupling, bunching, and fabrication.

Naranjo, B.; Ho, M.; Hoang, P.; Putterman, S.; Valloni, A.; Rosenzweig, J. B. [UCLA Dept. of Physics and Astronomy Los Angeles, CA 90095-1547 (United States)

2012-12-21T23:59:59.000Z

13

Effects of initially energetic electrons on relativistic laser-driven electron plasma waves  

SciTech Connect (OSTI)

In this paper, using kinetic calculations and accurate 1D2V particle-in-cell simulations, we point out the important role of initially energetic electrons of the distribution tail in the behavior of high amplitude electron plasma waves (EPWs). In the presence of these electrons, the conventional warm fluid theory (WFT) breaks at very high wave amplitudes that are still noticeably lower than the wave breaking amplitude (WBA). The fluid breakdown results in electron super-heating with respect to the adiabatic laws. Indeed, a new kinetic regime of the relativistic EPWs appears below the WBA. It is argued that the mentioned super-heating results in WBA values lower than the corresponding WFT prediction.

Yazdanpanah, J., E-mail: jamal.yazdan@gmail.com; Anvari, A. [Department of Physics, Sharif University of Technology, P.O. Box 1155-4161, Tehran (Iran, Islamic Republic of)] [Department of Physics, Sharif University of Technology, P.O. Box 1155-4161, Tehran (Iran, Islamic Republic of)

2014-02-15T23:59:59.000Z

14

Laser-Driven Fast Electron Collimation in Targets with Resistivity Boundary  

SciTech Connect (OSTI)

We demonstrate experimentally that the relativistic electron flow in a dense plasma can be efficiently confined and guided in targets exhibiting a high-resistivity-core-low-resistivity-cladding structure analogous to optical waveguides. The relativistic electron beam is shown to be confined to an area of the order of the core diameter (50 {mu}m), which has the potential to substantially enhance the coupling efficiency of electrons to the compressed fusion fuel in the Fast Ignitor fusion in full-scale fusion experiments.

Ramakrishna, B.; Kar, S.; Adams, D. J.; Markey, K.; Zepf, M. [School of Mathematics and Physics, Queen's University of Belfast, Belfast, BT7 1NN (United Kingdom); Robinson, A. P. L.; Lancaster, K. L.; Green, J. S.; Norreys, P. A. [Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Oxfordshire, OX11 0QX (United Kingdom); Quinn, M. N.; Yuan, X. H.; McKenna, P. [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Scott, R. H. H. [Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Oxfordshire, OX11 0QX (United Kingdom); Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom); Schreiber, J. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom)

2010-09-24T23:59:59.000Z

15

Compact disposal of high-energy electron beams using passive or laser-driven plasma decelerating stage  

SciTech Connect (OSTI)

A plasma decelerating stage is investigated as a compact alternative for the disposal of high-energy beams (beam dumps). This could benefit the design of laser-driven plasma accelerator (LPA) applications that require transportability and or high-repetition-rate operation regimes. Passive and laser-driven (active) plasma-based beam dumps are studied analytically and with particle-in-cell (PIC) simulations in a 1D geometry. Analytical estimates for the beam energy loss are compared to and extended by the PIC simulations, showing that with the proposed schemes a beam can be efficiently decelerated in a centimeter-scale distance.

Bonatto, A.; Schroeder, C.B.; Vay, J.-L.; Geddes, C.R.; Benedetti, C.; Esarey and, E.; Leemans, W.P.

2014-07-13T23:59:59.000Z

16

The structure of approximate two electron wavefunctions in intense laser driven ionization dynamics  

E-Print Network [OSTI]

The structure of approximate two electron wavefunction is deeply investigated, both theoretically and numerically, in the strong-field driven ionization dynamics. Theoretical analyses clarify that for two electron singlet systems, the previously proposed time-dependent extended Hartree-Fock (TD-EHF) method [Phys. Rev. A 51, 3999 (1995)] is equivalent to the multiconfiguration time-dependent Hartree-Fock method with two occupied orbitals. The latter wavefunction is further transformed into the natural expansion form, enabling the direct propagation of the natural orbitals (NOs). These methods, as well as the conventional time-dependent Hartree-Fock (TDHF) method, are numerically assessed for the description of ionization dynamics of one-dimensional helium atom model. This numerical analysis (i) explains the reason behind the well-known failure of TDHF method to describe tunneling ionization, (ii) demonstrates the interpretive power of the TD-EHF wavefunction both in the original nonorthogonal and the NO-based ...

Sato, Takeshi

2014-01-01T23:59:59.000Z

17

Direct observation of ultrafast surface transport of laser-driven fast electrons in a solid target  

SciTech Connect (OSTI)

We demonstrate rapid spread of surface ionization on a glass target excited by an intense, ultrashort laser pulse at an intensity of 3 × 10{sup 17} W cm{sup ?2}. Time- and space-resolved reflectivity of the target surface indicates that the initial plasma region created by the pump pulse expands at c/7. The measured quasi-static megagauss magnetic field is found to expand in a manner very similar to that of surface ionization. Two-dimensional particle-in-cell simulations reproduce measurements of surface ionization and magnetic fields. Both the experiment and simulation convincingly demonstrate the role of self-induced electric and magnetic fields in confining fast electrons along the target-vacuum interface.

Singh, Prashant Kumar; Chatterjee, Gourab; Adak, Amitava; Ahmed, Saima; Lad, Amit D.; Ravindra Kumar, G. [Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400005 (India)] [Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400005 (India); Cui, Y. Q.; Wang, W. M. [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China)] [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China); Sheng, Z. M. [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China) [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China); Key Laboratory for Laser Plasmas (MoE), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)

2013-11-15T23:59:59.000Z

18

Laser-driven fusion  

Science Journals Connector (OSTI)

The use of intense laser light to bring about thermonuclear reactions in a plasma is of considerable current interest. We present detailed analytical and computational studies which show the feasibility of laser-driven fusion. The required laser technology and the presently anticipated practical difficulties are discussed in outline.

Keith A. Brueckner and Siebe Jorna

1974-04-01T23:59:59.000Z

19

CONCEPTUAL DESIGN OF A BRIGHT ELECTRON INJECTOR BASED ON A LASER-DRIVEN PHOTOCATHODE RF ELECTRON GUN  

E-Print Network [OSTI]

Photocathode RF Electron Gun S. Chattopadhyay, Y.J. Chen, D.PHOTOCATHODE RF ELECTRON GUN' S. Chnttopndhyny. Y.J. Chen (Photocathode RF Electron Gun S. Chattopadhyay, Y.I. Chen, D.

Chattopadhyay, S.

2010-01-01T23:59:59.000Z

20

A global simulation for laser driven MeV electrons in $50\\mu m$-diameter fast ignition targets  

E-Print Network [OSTI]

The results from 2.5-dimensional Particle-in-Cell simulations for the interaction of a picosecond-long ignition laser pulse with a plasma pellet of 50-$\\mu m$ diameter and 40 critical density are presented. The high density pellet is surrounded by an underdense corona and is isolated by a vacuum region from the simulation box boundary. The laser pulse is shown to filament and create density channels on the laser-plasma interface. The density channels increase the laser absorption efficiency and help generate an energetic electron distribution with a large angular spread. The combined distribution of the forward-going energetic electrons and the induced return electrons is marginally unstable to the current filament instability. The ions play an important role in neutralizing the space charges induced by the the temperature disparity between different electron groups. No global coalescing of the current filaments resulted from the instability is observed, consistent with the observed large angular spread of th...

Ren, C; Fiore, M; Fonseca, R A; Héron, A; Mori, W B; Silva, L O; Tonge, J; Tsung, F S; Tzoufras, M

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Generation of high-quality mega-electron volt proton beams with intense-laser-driven nanotube accelerator  

SciTech Connect (OSTI)

An ion acceleration scheme using carbon nanotubes (CNTs) is proposed, in which embedded fragments of low-Z materials are irradiated by an ultrashort intense laser to eject substantial numbers of electrons. Due to the resultant characteristic electrostatic field, the nanotube and embedded materials play the roles of the barrel and bullets of a gun, respectively, to produce highly collimated and quasimonoenergetic ion beams. Three-dimensional particle simulations, that take all the two-body Coulomb interactions into account, demonstrate generation of quasimonoenergetic MeV-order proton beams using nanometer-size CNT under a super-intense electrostatic field {approx}10{sup 14} V m{sup -1}.

Murakami, M. [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan)] [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan); Tanaka, M. [Department of Engineering, Chubu University, Aichi 487-8501 (Japan)] [Department of Engineering, Chubu University, Aichi 487-8501 (Japan)

2013-04-22T23:59:59.000Z

22

2052 IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 35. NO. II, NOVEMBER 1988 Design of the Laser-Driven RF Electron Gun for the  

E-Print Network [OSTI]

-Driven RF Electron Gun for the BNL Accelerator Test Facility KIRK T. McDONALD Abstract-The BNL electron gun due to the effects of space-charge and nonlinear RF fields. The design of the gun was aided diagram of the linac and laser components. Here we report on the design of the electron gun

McDonald, Kirk

23

Using laser-driven neutrons to stop nuclear smugglers  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Using laser-driven neutrons to stop nuclear smugglers Using laser-driven neutrons to stop nuclear smugglers Researchers have successfully demonstrated for the first time that...

24

First time nuclear material detection by one short-pulse-laser-driven  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Articles » Articles » First time nuclear material detection by one short-pulse-laser-driven neutron source First time nuclear material detection by one short-pulse-laser-driven neutron source The results obtained are the first experimental demonstration of active interrogation of nuclear material by a short pulse laser driven neutron source. April 3, 2013 TRIDENT pulse The results obtained are the first experimental demonstration of active interrogation of nuclear material by a short pulse laser driven neutron source. Contact James Rickman Communications Specialist (505) 665-9203 Email A single shot interrogation of the depleted uranium sample, showed a clear signal from the delayed neutrons in the detector with uranium, compared with the background, and with the typical time behavior of delayed

25

Ultracold Electron Source  

Science Journals Connector (OSTI)

We propose a technique for producing electron bunches that has the potential for advancing the state-of-the-art in brightness of pulsed electron sources by orders of magnitude. In addition, this method leads to femtosecond bunch lengths without the use of ultrafast lasers or magnetic compression. The electron source we propose is an ultracold plasma with electron temperatures down to 10 K, which can be fashioned from a cloud of laser-cooled atoms by photoionization just above threshold. Here we present results of simulations in a realistic setting, showing that an ultracold plasma has an enormous potential as a bright electron source.

B. J. Claessens; S. B. van der Geer; G. Taban; E. J. D. Vredenbregt; O. J. Luiten

2005-10-12T23:59:59.000Z

26

Time-dependent restricted-active-space self-consistent-field theory for laser-driven many-electron dynamics. II. Extended formulation and numerical analysis  

E-Print Network [OSTI]

The time-dependent restricted-active-space self-consistent-field (TD-RASSCF) method is formulated based on the TD variational principle. In analogy with the configuration-interaction singles (CIS), singles-and-doubles (CISD), singles-doubles-and-triples (CISDT) methods in quantum chemistry, the TD-RASSCF-S, -SD, and -SDT methods are introduced as extensions of the TD-RASSCF dou- bles (-D) method [Phys. Rev. A 87, 062511 (2013)]. Based on an analysis of the numerical cost and test calculations for one-dimensional (1D) models of atomic helium, beryllium, and carbon, it is shown that the TD-RASSCF-S and -D methods are computationally feasible for systems with many electrons and more accurate than the TD Hartree-Fock (TDHF) and TDCIS methods. In addition to the discussion of methodology, an analysis of electron dynamics in the high-order harmonic generation (HHG) process is presented. For the 1D beryllium atom, a state-resolved analysis of the HHG spectrum based on the time-independent HF orbitals shows that while only single-orbital excitations are needed in the region below the cutoff, single- and double-orbital excitations are es- sential beyond, where accordingly the single-active-electron (SAE) approximation and the TDCIS method break down. On the other hand, the TD-RASSCF-S and -D methods accurately describe the multi-orbital excitation processes throughout the entire region of the HHG spectrum. For the 1D carbon atom, our calculations show that multi-orbital excitations are essential in the HHG process even below the cutoff. Hence, in this test system a very accurate treatment of electron correlation is required. The TD-RASSCF-S and -D approaches meet this demand, while the SAE approximation and the TDCIS method are inadequate.

Haruhide Miyagi; Lars Bojer Madsen

2014-05-21T23:59:59.000Z

27

Field emission electron source  

DOE Patents [OSTI]

A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

Zettl, Alexander Karlwalter (Kensington, CA); Cohen, Marvin Lou (Berkeley, CA)

2000-01-01T23:59:59.000Z

28

Laser-Driven Nuclear Fusion  

Science Journals Connector (OSTI)

Energy is set free not only by fission of heavy nuclei but also when the lightest nuclei fuse to form heavier ones. Such fusion processes are the energy source of our sun and other stars. Great effort is being...

S. Witkowski

1982-01-01T23:59:59.000Z

29

Laser-driven plasma-based accelerators: Wakefield excitation, channel guiding, and laser triggered particle injection*  

E-Print Network [OSTI]

Laser-driven plasma-based accelerators: Wakefield excitation, channel guiding, and laser triggered; accepted 18 February 1998 Plasma-based accelerators are discussed in which high-power short pulse lasers are the power source, suitably tailored plasma structures provide guiding of the laser beam and support large

Wurtele, Jonathan

30

Electron Beam Ion Sources  

E-Print Network [OSTI]

Electron beam ion sources (EBISs) are ion sources that work based on the principle of electron impact ionization, allowing the production of very highly charged ions. The ions produced can be extracted as a DC ion beam as well as ion pulses of different time structures. In comparison to most of the other known ion sources, EBISs feature ion beams with very good beam emittances and a low energy spread. Furthermore, EBISs are excellent sources of photons (X-rays, ultraviolet, extreme ultraviolet, visible light) from highly charged ions. This chapter gives an overview of EBIS physics, the principle of operation, and the known technical solutions. Using examples, the performance of EBISs as well as their applications in various fields of basic research, technology and medicine are discussed.

Zschornacka, G; Thorn, A

2013-01-01T23:59:59.000Z

31

Towards Laser Driven Hadron Cancer Radiotherapy: A Review of Progress  

E-Print Network [OSTI]

It has been known for about sixty years that proton and heavy ion therapy is a very powerful radiation procedure for treating tumours. It has an innate ability to irradiate tumours with greater doses and spatial selectivity compared with electron and photon therapy and hence is a tissue sparing procedure. For more than twenty years powerful lasers have generated high energy beams of protons and heavy ions and hence it has been frequently speculated that lasers could be used as an alternative to RF accelerators to produce the particle beams necessary for cancer therapy. The present paper reviews the progress made towards laser driven hadron cancer therapy and what has still to be accomplished to realise its inherent enormous potential.

Ledingham, K W D; Shikazono, N; Ma, C-M

2014-01-01T23:59:59.000Z

32

Laser-driven fusion etching process  

DOE Patents [OSTI]

The surfaces of solid ionic substrates are etched by a radiation-driven chemical reaction. The process involves exposing an ionic substrate coated with a layer of a reactant material on its surface to radiation, e.g. a laser, to induce localized melting of the substrate which results in the occurrance of a fusion reaction between the substrate and coating material. The resultant reaction product and excess reactant salt are then removed from the surface of the substrate with a solvent which is relatively inert towards the substrate. The laser-driven chemical etching process is especially suitable for etching ionic salt substrates, e.g., a solid inorganic salt such as LiNbO.sub.3, such as used in electro-optical/acousto-optic devices. It is also suitable for applications wherein the etching process is required to produce an etched ionic substrate having a smooth surface morphology or when a very rapid etching rate is desired.

Ashby, Carol I. H. (Edgewood, NM); Brannon, Paul J. (Albuquerque, NM); Gerardo, James B. (Albuquerque, NM)

1989-01-01T23:59:59.000Z

33

Laser-driven fusion etching process  

DOE Patents [OSTI]

The surfaces of solids are etched by a radiation-driven chemical reaction. The process involves exposing a substrate coated with a layer of a reactant material on its surface to radiation, e.g., a laser, to induce localized melting of the substrate which results in the occurrence of a fusion reaction between the substrate and coating material. The resultant reaction product and excess reactant salt are then removed from the surface of the substrate with a solvent which is relatively inert towards the substrate. The laser-driven chemical etching process is especially suitable for etching ionic substrates, e.g., LiNbO/sub 3/, such as used in electro-optical/acousto-optic devices. It is also suitable for applications wherein the etching process is required to produce an etched ionic substrate having a smooth surface morphology or when a very rapid etching rate is desired.

Ashby, C.I.H.; Brannon, P.J.; Gerardo, J.B.

1987-08-25T23:59:59.000Z

34

The Orsay Polarized Electron Source  

Science Journals Connector (OSTI)

A polarized electron source is developed at Orsay to equip existing ... have chosen to adapt the flowing helium afterglow source working at Rice University: it is able...

S. Essabaa; C. G. Aminoff; J. Arianer; I. Brissaud

1991-01-01T23:59:59.000Z

35

Using laser-driven neutrons to stop nuclear smugglers  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Using laser-driven neutrons to stop nuclear smugglers Using laser-driven neutrons to stop nuclear smugglers Using laser-driven neutrons to stop nuclear smugglers Researchers have successfully demonstrated for the first time that laser-generated neutrons can be enlisted as a useful tool in the War on Terror. June 4, 2013 A burst of laser energy 50 times greater than the worldwide output of electrical power slams into an extremely thin foil target to produce neutrons at Los Alamos National Laboratory's TRIDENT laser facility during a recent experiment, which proved that laser-driven neutrons can be used to detect and interdict smuggled nuclear materials. A burst of laser energy 50 times greater than the worldwide output of electrical power slams into an extremely thin foil target to produce neutrons at Los Alamos National Laboratory's TRIDENT laser facility during

36

Generation of 9 MeV -rays by all-laser-driven Compton scattering with second-harmonic laser light  

E-Print Network [OSTI]

Generation of 9 MeV -rays by all-laser-driven Compton scattering with second-harmonic laser light dura- tions (femtosecond). Pulses of -rays, electrons, and laser light are also well synchronized); published July 7, 2014 Gamma-ray photons with energy >9 MeV were produced when second

Umstadter, Donald

37

Carbon nanotube electron source technology  

Science Journals Connector (OSTI)

The carbon nanotube embodies a unique combination of properties which make it potentially an extraordinary field emission electron source. These properties include small tip radii (and small source size), high el...

Kenneth Teo

2007-03-01T23:59:59.000Z

38

The SLC Polarized Electron Source  

Science Journals Connector (OSTI)

A polarized electron source consisting of a 3-electrode photocathode gun ... SLC and is currently undergoing commissioning. The source is described, and the operating configuration is discussed. The present statu...

J. E. Clendenin

1991-01-01T23:59:59.000Z

39

E-Print Network 3.0 - atom laser driven Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

laser driven Search Powered by Explorit Topic List Advanced Search Sample search results for: atom laser driven Page: << < 1 2 3 4 5 > >> 1 (For McGraw-Hill 1999 Yearbook of...

40

Diamondoid Monolayers as Monochromatic Electron Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Diamondoid Monolayers as Monochromatic Electron Source Diamondoid Monolayers as Monochromatic Electron Source Print Wednesday, 28 November 2007 00:00 Diamondoids are...

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Electron cooling for positron sources  

Science Journals Connector (OSTI)

Electron cooling of positrons should make possible a large increase in the luminosity of future high-energy linear colliders, leading to greatly enhanced event rates at these machines. An evaluation of the electron-cooling-time requirement indicates that a positron-source repetition rate of 100 Hz is possible. Final positron-beam normalized emittances of 10-7 m rad should result, implying a tremendous increase in positron-beam density over that currently obtained.

D. J. Larson

1988-03-28T23:59:59.000Z

42

A Micromachined Electron Beam Ion Source  

Science Journals Connector (OSTI)

The complete ion source consists of two parts: an RF-plasma electron source, the linked up optic which focuses the electron beam into the second part, the ionization...

G. Petzold; P. Siebert; J. Müller

2000-01-01T23:59:59.000Z

43

MIS-1 electron-beam ion source  

Science Journals Connector (OSTI)

The Institute of Nuclear Physics (INP) has developed and produced electron-beam multiply charged ion sources. These ion sources give the electron beam its high density in the ionization...3 A/cm2.... They produce...

V. G. Abdulmanov; N. S. Dikansky

2010-12-01T23:59:59.000Z

44

ECR ion source with electron gun  

DOE Patents [OSTI]

An Advanced Electron Cyclotron Resonance ion source having an electron gun for introducing electrons into the plasma chamber of the ion source is described. The ion source has a injection enclosure and a plasma chamber tank. The plasma chamber is defined by a plurality of longitudinal magnets. The electron gun injects electrons axially into the plasma chamber such that ionization within the plasma chamber occurs in the presence of the additional electrons produced by the electron gun. The electron gun has a cathode for emitting electrons therefrom which is heated by current supplied from an AC power supply while bias potential is provided by a bias power supply. A concentric inner conductor and outer conductor carry heating current to a carbon chuck and carbon pusher which hold the cathode in place and also heat the cathode. In the Advanced Electron Cyclotron Resonance ion source, the electron gun replaces the conventional first stage used in prior electron cyclotron resonance ion generators. 5 figures.

Xie, Z.Q.; Lyneis, C.M.

1993-10-26T23:59:59.000Z

45

Simulation ensemble for a laser–driven shear experiment  

SciTech Connect (OSTI)

We perform an ensemble of simulations of a laser-driven shear experiment [L. Welser-Sherrill et al., “Two laser-driven mix experiments to study reshock and shear,” High Energy Density Phys. J. 9(3), 496–499 (2013)] in the strong-shock high energy-density regime to better understand material mixing driven by the Kelvin–Helmholtz instability. Each simulation uses a different realization of random initial interface perturbations based on data from targets used in experiments. Validation of the simulations is based on direct comparison of simulation and radiographic data. Simulations are also compared with published direct numerical simulation and the theory of homogeneous isotropic turbulence. Despite the fact that the flow is neither homogeneous, isotropic, nor fully turbulent, there are local regions in which the flow demonstrates characteristics of homogeneous isotropic turbulence. Our analysis shows characteristics consistent with those of incompressible isotropic turbulence. Our results show that turbulent features are present both near the shock front and in a separated region in the wake of the shock. These features develop and decay at different rates. Finally, we use the ensemble of three-dimensional simulations to test the performance of two-dimensional Reynolds-averaged Navier-Stokes simulations. In this context, we also test a presumed probability density function turbulent mixing model extensively used in combustion applications.

Haines, Brian M.; Grinstein, Fernando F.; Welser–Sherrill, Leslie; Fincke, James R.; Doss, Forrest W. [Los Alamos National Laboratory, MS T087, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, MS T087, Los Alamos, New Mexico 87545 (United States)

2013-09-15T23:59:59.000Z

46

Laser-driven shock experiments in pre-compressed water: Implications for magnetic field generation in Icy Giant planets  

SciTech Connect (OSTI)

Laser-driven shock compression of pre-compressed water (up to 1 GPa precompression) produces high-pressure, -temperature conditions in the water inducing two optical phenomena: opacity and reflectivity in the initially transparent water. The onset of reflectivity at infrared wavelengths can be interpreted as a semi-conductor to electronic conductor transition in water and is found at pressures above {approx}130 GPa for single-shocked samples pre-compressed to 1 GPa. This electronic conduction provides an additional contribution to the conductivity required for magnetic field generation in Icy Giant planets like Uranus and Neptune.

Lee, K; Benedetti, L R; Jeanloz, R; Celliers, P M; Eggert, J H; Hicks, D G; Moon, S J; Mackinnon, A; Henry, E; Koenig, M; Benuzzi-Mounaix, A; Collins, G W

2005-11-10T23:59:59.000Z

47

Acceleration-field calculation for a structure-based laser-driven linear accelerator  

E-Print Network [OSTI]

Acceleration-field calculation for a structure-based laser-driven linear accelerator Y. C. Huanga for publication 16 April 1998 A laser-driven particle accelerator, scaled to optical wavelengths, has a feature size many orders of magnitude smaller than a radio-frequency accelerator. However, similar to a radio

Byer, Robert L.

48

Secondary electron ion source neutron generator  

DOE Patents [OSTI]

A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter. The target contains occluded deuterium, tritium, or a mixture thereof

Brainard, John P. (Albuquerque, NM); McCollister, Daryl R. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

49

Secondary electron ion source neutron generator  

DOE Patents [OSTI]

A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter is disclosed. The target contains occluded deuterium, tritium, or a mixture thereof. 4 figs.

Brainard, J.P.; McCollister, D.R.

1998-04-28T23:59:59.000Z

50

Diamondoid Monolayers as Monochromatic Electron Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Diamondoid Monolayers as Monochromatic Electron Source Print Diamondoids are nanometer-sized molecules that feature diamond-crystal cage structures. Adamantane, the smallest member...

51

ECR ion source with electron gun  

DOE Patents [OSTI]

An Advanced Electron Cyclotron Resonance ion source (10) having an electron gun (52) for introducing electrons into the plasma chamber (18) of the ion source (10). The ion source (10) has a injection enclosure (12) and a plasma chamber tank (14). The plasma chamber (18) is defined by a plurality of longitudinal magnets (16). The electron gun (52) injects electrons axially into the plasma chamber (18) such that ionization within the plasma chamber (18) occurs in the presence of the additional electrons produced by the electron gun (52). The electron gun (52) has a cathode (116) for emitting electrons therefrom which is heated by current supplied from an AC power supply (96) while bias potential is provided by a bias power supply (118). A concentric inner conductor (60) and Outer conductor (62) carry heating current to a carbon chuck (104) and carbon pusher (114) Which hold the cathode (116) in place and also heat the cathode (16). In the Advanced Electron Cyclotron Resonance ion source (10), the electron gun (52) replaces the conventional first stage used in prior art electron cyclotron resonance ion generators.

Xie, Zu Q. (El Cerrito, CA); Lyneis, Claude M. (Berkeley, CA)

1993-01-01T23:59:59.000Z

52

Glauber coherence of single-electron sources  

Science Journals Connector (OSTI)

Recently demonstrated solid-state single-electron sources generate different quantum states depending on their operation condition. For adiabatic and nonadiabatic sources, we determine the Glauber correlation function in terms of the Floquet scattering matrix of the source. The correlation function provides full information on the shape of the state and on its time-dependent amplitude and phase. The coherence properties of single-electron states are therefore essential for the production of quantum multiparticle states.

G. Haack; M. Moskalets; M. Büttiker

2013-05-17T23:59:59.000Z

53

Detailed study of nuclear fusion from femtosecond laser-driven explosions of deuterium clusters  

E-Print Network [OSTI]

Detailed study of nuclear fusion from femtosecond laser-driven explosions of deuterium clusters J that these clusters can explode with sufficient kinetic energy to drive nuclear fusion. Irradiating deuterium clusters

Ditmire, Todd

54

Plasma-Density Determination from X-Ray Radiography of Laser-Driven Spherical Implosions  

E-Print Network [OSTI]

The fuel layer density of an imploding laser-driven spherical shell is inferred from framed x-ray radiographs. The density distribution is determined by using Abel inversion to compute the radial distribution of the opacity ...

Frenje, Johan A.

55

Periodic thermodynamics of laser-driven molecular motor  

Science Journals Connector (OSTI)

Operation of a laser-driven nano-motor inevitably generates a non-trivial amount of heat, which can possibly lead to instability or even hinder the motor's continual running. This work quantitatively examines the overheating problem for a recently proposed laser-operated molecular locomotive. We present a single-molecule cooling theory, in which molecular details of the locomotive system are explicitly treated. This theory is able to quantitatively predict cooling efficiency for various candidates of molecular systems for the locomotive, and also suggests concrete strategies for improving the locomotive's cooling. It is found that water environment is able to cool the hot locomotive down to room temperature within 100 picoseconds after photon absorption. This cooling time is a few orders of magnitude shorter than the typical time for laser operation, effectively preventing any overheating for the nano-locomotive. However, when the cooling is less effective in non-aqueous environment, residual heat may build up. A continuous running of the motor will then lead to a periodic thermodynamics, which is a common character of many laser-operated nano-devices.

Li Dan; Zheng Wen-Wei; Wang Zhi-Song

2008-01-01T23:59:59.000Z

56

The Electron Beam Ion Source (EBIS)  

ScienceCinema (OSTI)

Brookhaven National Lab has successfully developed a new pre-injector system, called the Electron Beam Ion Source, for the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory science programs. The first of several planned improvemen

Brookhaven Lab

2010-01-08T23:59:59.000Z

57

The Electron Beam Ion Source (EBIS)  

SciTech Connect (OSTI)

Brookhaven National Lab has successfully developed a new pre-injector system, called the Electron Beam Ion Source, for the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory science programs. The first of several planned improvemen

Brookhaven Lab

2009-06-09T23:59:59.000Z

58

Theory and proposal for a quantum-degenerate electron source  

E-Print Network [OSTI]

for a quantum-degenerate electron source M. Zolotorev, E. D.propose a pulsed electron source capable of a 6D brightnesspropose a pulsed electron source with brightness approaching

Zolotorev, Max; Commins, Eugene D.; Sannibale Fernando

2006-01-01T23:59:59.000Z

59

ELECTRON SUPPRESSION IN A MULTI-CUSP NEGATIVE ION SOURCE  

E-Print Network [OSTI]

very low energy electrons at the source exit (Fig. 2). TheTo suppress the electrons at the source exit in this multi-energy primary electrons into the source plasma. The energy

Ehlers, K.W.

2013-01-01T23:59:59.000Z

60

Stimulated scattering in laser driven fusion and high energy density physics experiments  

SciTech Connect (OSTI)

In laser driven fusion and high energy density physics experiments, one often encounters a k?{sub D} range of 0.15?electron plasma wave number and ?{sub D} is the Debye length). Using particle-in-cell simulations, the SRS reflectivity is found to scale as ? (k?{sub D}){sup ?4} for k?{sub D} ? 0.3 where electron trapping effects dominate SRS saturation; the reflectivity scaling deviates from the above for k?{sub D}?electron temperature variation from collisional heating, the latter of which reduces gain, introduces a positive frequency shift that counters the trapping-induced negative frequency shift, and affects SRS and SBS saturation. Bowing and breakup of ion-acoustic wavefronts saturate SBS and cause a dramatic, sharp decrease in SBS reflectivity. Mitigation of SRS and SBS in the strongly nonlinear trapping regime is discussed.

Yin, L., E-mail: lyin@lanl.gov; Albright, B. J.; Rose, H. A.; Montgomery, D. S.; Kline, J. L.; Finnegan, S. M.; Bergen, B.; Bowers, K. J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kirkwood, R. K.; Milovich, J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2014-09-15T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Bates GaAs polarized electron source  

SciTech Connect (OSTI)

In order to pursue measurements of parity violating effects of the neutral weak current, we have developed a polarized electron source suitable for installation at the MIT-Bates Linear Accelerator. The source is designed to provide a high peak-current pulsed beam that has a approx. 1% duty factor and that is extremely stable under helicity reversal. 34 references, 6 figures, 1 table.

Schaefer, H.R.; Cates, G.; Michaels, R.; Hughes, V.W.. Lubell, M.S.; Souder, P.A.

1983-05-01T23:59:59.000Z

62

Revealing Electron Delocalization through the Source Function  

Science Journals Connector (OSTI)

The source function (SF) introduced in late 90s by Bader and Gatti quantifies the influence of each atom in a system in determining the amount of electron density at a given point, regardless of the atom’s remote or close location with respect to the ...

Emanuele Monza; Carlo Gatti; Leonardo Lo Presti; Emanuele Ortoleva

2011-07-15T23:59:59.000Z

63

Positron source position sensing detector and electronics  

DOE Patents [OSTI]

A positron source, position sensing device, particularly with medical applications, in which positron induced gamma radiation is detected using a ring of stacked, individual scintillation crystals, a plurality of photodetectors, separated from the scintillation crystals by a light guide, and high resolution position interpolation electronics. Preferably the scintillation crystals are several times more numerous than the photodetectors with each crystal being responsible for a single scintillation event from a received gamma ray. The light guide will disperse the light emitted from gamma ray absorption over several photodetectors. Processing electronics for the output of the photodetectors resolves the location of the scintillation event to a fraction of the dimension of each photodetector. Because each positron absorption results in two 180.degree. oppositely traveling gamma rays, the detection of scintillation in pairs permits location of the positron source in a manner useful for diagnostic purposes. The processing electronics simultaneously responds to the outputs of the photodetectors to locate the scintillations to the source crystal. While it is preferable that the scintillation crystal include a plurality of stacked crystal elements, the resolving power of the processing electronics is also applicable to continuous crystal scintillators.

Burnham, Charles A. (South Essex, MA); Bradshaw, Jr., John F. (Winthrop, MA); Kaufman, David E. (Brockton, MA); Chesler, David A. (Newton Highlands, MA); Brownell, Gordon L. (Cambridge, MA)

1985-01-01T23:59:59.000Z

64

Visualization of Trajectories of Electron Beams Emitted by an Ion Source with Closed Electron Drift  

E-Print Network [OSTI]

that this additional electron source is not able to provideare a source of additional electrons that partiallyEmitted by an Ion Source with Closed Electron Drift Ivan V.

Bordenjuk, Ian V.; Institue of Physics, National Academy of Sciences of Ukraine

2008-01-01T23:59:59.000Z

65

CONSTRAINTS ON LASER-DRIVEN ACCELERATORS FOR A HIGH-ENERGY LINEAR COLLIDER*  

E-Print Network [OSTI]

CONSTRAINTS ON LASER-DRIVEN ACCELERATORS FOR A HIGH-ENERGY LINEAR COLLIDER* J.S. Wurtele and AV on 1 TeV) are applied to free-space laser and laser/plasma accelerators. It is shown that the requirements impose very severe constraints upon the new accelerators-- so severe, that it seems unlikely

Wurtele, Jonathan

66

Update on the Electron Source Model  

SciTech Connect (OSTI)

We summarize work done in FY12 on the Los Alamos Electron Source Model (ESM), which predicts the distribution of beta-decay electrons after a high altitude nuclear explosion (HANE) as a function of L, energy, and pitch angle. In the last year we have compared model results with data taken after the Russian 2 HANE test of 1962 and presented results at the HEART conference. We discuss our future plans to continue comparison with HANE data and to develop the code to allow a more complex set of initial conditions.

Cowee, Misa [Los Alamos National Laboratory; Winske, Dan [Los Alamos National Laboratory

2012-07-17T23:59:59.000Z

67

Diamondoid Monolayers as Monochromatic Electron Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Diamondoid Monolayers as Monochromatic Electron Source Print Diamondoid Monolayers as Monochromatic Electron Source Print Diamondoids are nanometer-sized molecules that feature diamond-crystal cage structures. Adamantane, the smallest member in the family, consists of one cage structure, diamantane two, triamantane three, tetramantane four, and so on. On all of these, the dangling bonds on the outer surfaces are terminated by hydrogen atoms. Because of their potential to possess novel properties of both diamond and nanomaterial, intensive efforts have been made to synthesize the larger diamondoid molecules, but to no avail. This situation was finally changed in 2003 when significant quantities of higher diamondoids were found in petroleum by researchers in MolecularDiamond Technologies. Now, scientists from Berkeley Lab, Stanford University, Lawrence Livermore National Laboratory, and Germany have used photoelectron spectroscopy at the ALS to reveal an intriguing feature: monochromatized electron emission from a self-assembled monolayer of diamondoids. This discovery has immediately attracted the attention of people who are searching for materials for next-generation electron emitters.

68

Diamondoid Monolayers as Monochromatic Electron Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Diamondoid Monolayers as Monochromatic Electron Source Print Diamondoid Monolayers as Monochromatic Electron Source Print Diamondoids are nanometer-sized molecules that feature diamond-crystal cage structures. Adamantane, the smallest member in the family, consists of one cage structure, diamantane two, triamantane three, tetramantane four, and so on. On all of these, the dangling bonds on the outer surfaces are terminated by hydrogen atoms. Because of their potential to possess novel properties of both diamond and nanomaterial, intensive efforts have been made to synthesize the larger diamondoid molecules, but to no avail. This situation was finally changed in 2003 when significant quantities of higher diamondoids were found in petroleum by researchers in MolecularDiamond Technologies. Now, scientists from Berkeley Lab, Stanford University, Lawrence Livermore National Laboratory, and Germany have used photoelectron spectroscopy at the ALS to reveal an intriguing feature: monochromatized electron emission from a self-assembled monolayer of diamondoids. This discovery has immediately attracted the attention of people who are searching for materials for next-generation electron emitters.

69

Progress with Optically Pumped Sources of Polarized Electrons  

E-Print Network [OSTI]

Progress with Optically Pumped Sources of Polarized Electrons M.A. Rosenberry, H. Batelaan, J. We report our work in developing new "turn-key" sources of polarized electrons. These sources operate], and the chiral structure of molecules [3]. At present the standard source of polarized electrons is a specially

Gay, Timothy J.

70

Stripped electron collection at the Spallation Neutron Source  

Science Journals Connector (OSTI)

One of the main sources of electrons in the Spallation Neutron Source’s Accumulator Ring is the stripped electrons in the injection region. A magnetic field guides the stripped electrons to the bottom of the beam pipe, where an electron catcher with overhanging surface traps them. This paper describes the stripped electrons’ motion, the optimization of the catcher, and the build up of an electron cloud in this region.

L. Wang; Y. Y. Lee; G. Mahler; W. Meng; D. Raparia; J. Wei; S. Henderson

2005-09-13T23:59:59.000Z

71

Physics of Laser-driven plasma-based acceleration  

SciTech Connect (OSTI)

The physics of plasma-based accelerators driven by short-pulse lasers is reviewed. This includes the laser wake-field accelerator, the plasma beat wave accelerator, the self-modulated laser wake-field accelerator, and plasma waves driven by multiple laser pulses. The properties of linear and nonlinear plasma waves are discussed, as well as electron acceleration in plasma waves. Methods for injecting and trapping plasma electrons in plasma waves are also discussed. Limits to the electron energy gain are summarized, including laser pulse direction, electron dephasing, laser pulse energy depletion, as well as beam loading limitations. The basic physics of laser pulse evolution in underdense plasmas is also reviewed. This includes the propagation, self-focusing, and guiding of laser pulses in uniform plasmas and plasmas with preformed density channels. Instabilities relevant to intense short-pulse laser-plasma interactions, such as Raman, self-modulation, and hose instabilities, are discussed. Recent experimental results are summarized.

Esarey, Eric; Schroeder, Carl B.

2003-06-30T23:59:59.000Z

72

Cold Electron Source with an Electron Multiplier Illuminated by Ultraviolet Photons  

Science Journals Connector (OSTI)

The most common electron source for EI is a hot cathode which creates a stream of electrons via thermionic emission from a metal surface. ... The result shows that an MCP cold electron source with a UV diode as the photon generator has a number of advantages over thermionic emission sources or alternate cold electron sources. ...

Hyun Sik Kim; Seung Yong Kim; Mo Yang

2012-03-12T23:59:59.000Z

73

Laser-driven relativistic tunneling from p-states  

E-Print Network [OSTI]

The tunneling ionization of an electron from a p-state in a highly charged ion in the relativistic regime is investigated in a linearly polarized strong laser field. In contrast to the case of an s-state, the tunneling ionization from the p-state is spin asymmetric. We have singled out two reasons for the spin asymmetry: first, the difference of the electron energy Zeeman splitting in the bound state and during tunneling, and second, the relativistic momentum shift along the laser propagation direction during the under-the barrier motion. Due to the latter, those states are predominantly ionized where the electron rotation is opposite to the electron relativistic shift during the under-the-barrier motion. We have investigated the dependence of the ionization rate on the laser intensity for different projections of the total angular momentum and identified the intensity parameter which governs this behaviour. The significant change of the ionization rate is originated from the different precession dynamics of the total angular momentum in the bound state at high and low intensities.

Michael Klaiber; Karen Z. Hatsagortsyan

2014-10-20T23:59:59.000Z

74

Electron sources in Saturn's magnetosphere A. M. Rymer,1  

E-Print Network [OSTI]

Electron sources in Saturn's magnetosphere A. M. Rymer,1 B. H. Mauk,1 T. W. Hill,2 C. Paranicas,1 N electrons (source in the inner magnetosphere and are likely products of neutral ionization itself as a source of electrons at given invariant values in our f(v) analyses. We show that Coulomb

Johnson, Robert E.

75

Electron Beam Ion Source Pre-Injector Diagnostics  

E-Print Network [OSTI]

Electron Beam Ion Source Pre-Injector Diagnostics M. Wilinski, J. Alessi, E. Beebe, S. Bellavia, A. This pre-injector is based on an Electron Beam Ion Source (EBIS), a Radio Frequency Quadrupole (RFQ, current transformer, pepperpot, electron beam ion source PACS: 29.17.+w, 29.25.Ni, 29.27.Fh INTRODUCTION

76

Interference between two indistinguishable electrons from independent sources  

E-Print Network [OSTI]

LETTERS Interference between two indistinguishable electrons from independent sources I. Neder1 , N of the electrons (`wave packet width' or `spatial size') is determined by the source voltage (at low temperature), a very small source voltage ensures the presence of a single electron at a time in the interferometer

Heiblum, Mordehai "Moty"

77

Laser-driven acceleration of a dense matter up to 'thermonuclear' velocities  

Science Journals Connector (OSTI)

The results of theoretical studies and numerical simulations of laser-driven acceleration of a flat foil up to ultrahigh velocity of the order of 1000?km?s?1, which corresponds to the achievement of thermonuclear temperatures due to kinetic energy transition into thermal energy at an inelastic impact, are reported. The behavior of a foil accelerated to such high velocities, in particular, the distribution of foil density, which defines thermonuclear reaction intensity, has been studied. The calculation results are compared with the results of the experiments performed on the Gekko/HIPER laser, where a laser-driven projectile achieved record-breaking velocity. The laser pulse and foil parameters responsible for acceleration of the projectile up to 'thermonuclear' velocities in a dense state have been determined.

S Yu Gus'kov; H Azechi; N N Demchenko; V V Demchenko; I Ya Doskoch; M Murakami; H Nagatomo; V B Rozanov; S Sakaiya; R V Stepanov; N V Zmitrenko

2007-01-01T23:59:59.000Z

78

Quantum description and properties of electrons emitted from pulsed nanotip electron sources  

Science Journals Connector (OSTI)

We present a quantum calculation of the electron degeneracy for electron sources. We explore quantum interference of electrons in the temporal and spatial domain and demonstrate how it can be utilized to characterize a pulsed electron source. We estimate effects of Coulomb repulsion on two-electron interference and show that currently available pulsed nanotip electron sources operate in the regime where the quantum nature of electrons can be made dominant.

Pavel Lougovski and Herman Batelaan

2011-08-29T23:59:59.000Z

79

Advances in laser driven accelerator R&D  

SciTech Connect (OSTI)

Current activities (last few years) at different laboratories, towards the development of a laser wakefield accelerator (LWFA) are reviewed, followed by a more in depth discussion of results obtained at the L'OASIS laboratory of LBNL. Recent results on laser guiding of relativistically intense beams in preformed plasma channels are discussed. The observation of mono-energetic beams in the 100 MeV energy range, produced by a channel guided LWFA at LBNL, is described and compared to results obtained in the unguided case at LOA, RAL and LBNL. Analysis, aided by particle-in-cell simulations, as well as experiments with various plasma lengths and densities, indicate that tailoring the length of the accelerator has a very beneficial impact on the electron energy distribution. Progress on laser triggered injection is reviewed. Results are presented on measurements of bunch duration and emittance of the accelerated electron beams, that indicate the possibility of generating femtosecond duration electron bunches. Future challenges and plans towards the development of a 1 GeV LWFA module are discussed.

Leemans, Wim

2004-08-23T23:59:59.000Z

80

SPALLATION NEUTRON SOURCE BEAM CURRENT MONITOR ELECTRONICS.  

SciTech Connect (OSTI)

The Spallation Neutron Source (SNS) to be constructed at ORNL is a collaboration of six laboratories. Beam current monitors for SNS will be used to monitor H-minus and H-plus beams ranging from the 15 mA (tune-up in the Front End and Linac) to over 60 A fully accumulated in the Ring. The time structure of the beams to be measured range from 645 nsec ''mini'' bunches, at the 1.05 MHz ring revolution rate, to an overall 1 mS long macro pulse. Beam current monitors (BCMs) for SNS have requirements depending upon their location within the system. The development of a general approach to satisfy requirements of various locations with common components is a major design objective. This paper will describe the development of the beam current monitors and electronics.

KESSELMAN, M.

2001-06-18T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Ion acceleration from laser-driven electrostatic shocks  

SciTech Connect (OSTI)

Multi-dimensional particle-in-cell simulations are used to study the generation of electrostatic shocks in plasma and the reflection of background ions to produce high-quality and high-energy ion beams. Electrostatic shocks are driven by the interaction of two plasmas with different density and/or relative drift velocity. The energy and number of ions reflected by the shock increase with increasing density ratio and relative drift velocity between the two interacting plasmas. It is shown that the interaction of intense lasers with tailored near-critical density plasmas allows for the efficient heating of the plasma electrons and steepening of the plasma profile at the critical density interface, leading to the generation of high-velocity shock structures and high-energy ion beams. Our results indicate that high-quality 200 MeV shock-accelerated ion beams required for medical applications may be obtained with current laser systems.

Fiuza, F.; Stockem, A.; Boella, E.; Fonseca, R. A.; Silva, L. O. [GoLP—Instituto de Plasmas e Fusão Nuclear—Laboratório Associado, Instituto Superior Técnico, 1049-001 Lisbon (Portugal)] [GoLP—Instituto de Plasmas e Fusão Nuclear—Laboratório Associado, Instituto Superior Técnico, 1049-001 Lisbon (Portugal); Haberberger, D.; Tochitsky, S.; Mori, W. B.; Joshi, C. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States)] [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States)

2013-05-15T23:59:59.000Z

82

Laser Electron Gamma Source. Biennial progress report  

SciTech Connect (OSTI)

The LEGS facility provides intense, polarized, monochromatic {gamma}-ray beams by Compton backscattering laser light from relativistic electrons circulating in the X-Ray storage ring of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. With the start of ring operations at 2.8 GeV, LEGS {gamma}-ray energies now extend to 370 MeV. Considerable progress has been made in the development of a new laser system that will increase the beam energies to 470 MeV, and this system is expected to come into operation before the next biennial report. The total flux is administratively held at 6 {times} 10{sup 6} s{sup {minus}1}. The {gamma}-ray energy is determined, with a resolution of 5.5 MeV, by detecting the scattering electrons in a magnetic spectrometer. This spectrometer can `tag` all {gamma}-rays with energies from 185 MeV up to the Compton edge. The beam spot size at the target position is 8 mm (V) {times} 18 mm (H), FWHM. For a single laser wavelength, the linear polarization of the beam is 98% at the Compton edge and decreases to 50% at about 1/2 the energy of the edge. By choosing the laser wavelengths appropriately the polarization can be maintained above 85% throughout the tagging range. During the last two years, experimental running at LEGS occupied an average of 3000 hours annually. Highlights of some of the programs are discussed below.

Sandorfi, A.M. [ed.; Caracappa, A.; Kuczewski, A.; Kistner, O.C.; Lincoln, F.; Miceli, L.; Thorn, C.E. [Brookhaven National Lab., Upton, NY (United States); Hoblit, S. [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Physics; Khandaker, M. [Brookhaven National Lab., Upton, NY (United States)]|[Virginia Polytechnic Institute & State Univ., Blacksburg, VA (United States). Dept. of Physics

1994-06-01T23:59:59.000Z

83

High-current-density, high brightness cathodes for free electron laser applications  

SciTech Connect (OSTI)

This report discusses the following topics: brightness and emittance of electron beams and cathodes; general requirements for cathodes in high brightness electron guns; candidate cathode types; plasma and field emission cathodes; true field emission cathodes; oxide cathodes; lanthanum hexaborides cathodes; laser driven thermionic cathodes; laser driven photocathodes; impregnated porous tungsten dispenser cathodes; and choice of best performing cathode types.

Green, M.C. (Varian Associates, Palo Alto, CA (USA). Palo Alto Microwave Tube Div.)

1987-06-01T23:59:59.000Z

84

Interaction of cathode plasma with the cathode surface in an electron source with explosive electron emission  

Science Journals Connector (OSTI)

The interaction of the plasma formed at emission centers of an electron source using explosive electron emission with the cathode surface is studied....

É. N. Abdullin; G. P. Bazhenov

1981-11-01T23:59:59.000Z

85

FIRST EXPERIMENTAL RESULTS FROM DEGAS, THE QUANTUM LIMITED BRIGHTNESS ELECTRON SOURCE  

E-Print Network [OSTI]

LIMITED BRIGHTNESS ELECTRON SOURCE* M. S. Zolotorev 1 , E.limited brightness electron source, has been completed atand by a thermionic electron source placed at the DEGAS IR

Zolotorev, Max S.

2008-01-01T23:59:59.000Z

86

Femtosecond electron and x-ray generation by laser and plasma-based sources  

E-Print Network [OSTI]

Although conventional electron sources (photocathode orof these conventional electron sources. Novel schemes which11, 2000 These laser-electron beam sources o?er some unique

Esarey, E.; Leemans, W.P.

2000-01-01T23:59:59.000Z

87

VERIFIABLE ELECTRONIC VOTING SYSTEM: AN OPEN SOURCE SOLUTION  

E-Print Network [OSTI]

VERIFIABLE ELECTRONIC VOTING SYSTEM: AN OPEN SOURCE SOLUTION Halina Kaminski* and Mark Perry over existing network system. KEY WORDS Free Libre Open Source Software; Electronic Voting; Security in managing the election process through the use of electronic voting systems. While computer scientists

Perry, Mark

88

Electron Diffraction from a Cold Atom Electron Source  

Science Journals Connector (OSTI)

We present single-shot nanosecond and picosecond electron diffraction measurements from gold and graphene using ultracold electrons generated by photoionisation of laser cooled atoms.

Speirs, Rory W; Thompson, Daniel J; Murphy, Dene; Sparkes, Ben M; Scholten, Rob E

89

Analytical model of an isolated single-atom electron source  

Science Journals Connector (OSTI)

Abstract An analytical model of a single-atom electron source is presented, where electrons are created by near-threshold photoionization of an isolated atom. The model considers the classical dynamics of the electron just after the photon absorption, i.e. its motion in the potential of a singly charged ion and a uniform electric field used for acceleration. From closed expressions for the asymptotic transverse electron velocities and trajectories, the effective source temperature and the virtual source size can be calculated. The influence of the acceleration field strength and the ionization laser energy on these properties has been studied. With this model, a single-atom electron source with the optimum electron beam properties can be designed. Furthermore, we show that the model is also applicable to ionization of rubidium atoms, and thus also describes the ultracold electron source, which is based on photoionization of laser-cooled alkali atoms.

W.J. Engelen; E.J.D. Vredenbregt; O.J. Luiten

2014-01-01T23:59:59.000Z

90

ILC Electron Source Gets Help from JLab | Jefferson Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

electrode The cathode electrode is being put to the test in Jefferson Lab's electron gun test stand. This work is part of a research project on the ILC's electron source, which...

91

Status of the Kharkov Linac Polarized Electron Source  

Science Journals Connector (OSTI)

In this note we briefly describe the GaAs polarized electron source, which is the full-scale injector prototype for the electron linear accelerator of the Kharkov Institute of...

V. L. Agranovich; A. V. Glamazdin; V. G. Gorbenko…

1991-01-01T23:59:59.000Z

92

A forevacuum pulse arc-discharge-based plasma electron source  

Science Journals Connector (OSTI)

An arc-discharge-based electron source is described, which is designed for forming a pulsed wideaperture electron beam in the forevacuum pressure range (4...2 in the submillisecond range of pulse durations. The c...

A. V. Kazakov; V. A. Burdovitsin; A. V. Medovnik…

2013-11-01T23:59:59.000Z

93

On the possibility of electron-beam processing of dielectrics using a forevacuum plasma electron source  

Science Journals Connector (OSTI)

An insulated target was irradiated by an electron beam generated by a forevacuum plasma electron source operating in the pressure range of 5– ... showed that plasma formed in the region of electron beam transport...

V. A. Burdovitsin; A. S. Klimov; E. M. Oks

2009-06-01T23:59:59.000Z

94

Experimental studies of electron and gas sources in a heavy-ion beam  

E-Print Network [OSTI]

measured with the Gas-Electron Source Diagnostic (GESD) [6].EXPERIMENTAL STUDIES OF ELECTRON AND GAS SOURCES IN A HEAVY-

2004-01-01T23:59:59.000Z

95

An Ultracold Electron Source for Ultrafast Electron Diffraction Experiments  

Science Journals Connector (OSTI)

We create ultrashort, ultracold electron bunches by accelerating electrons which are created by near-threshold photoionization of a cloud of laser-cooled atoms. With these bunches we...

Engelen, Wouter; Debernardi, Nicola; Vredenbregt, Edgar; Luiten, Jom

96

Optically pumped spin-exchange polarized-electron source  

Science Journals Connector (OSTI)

We describe the operation of a prototype polarized-electron source. Rubidium vapor, contained in a cell, is optically pumped in the presence of a buffer gas. Unpolarized electrons from a tungsten filament are injected into the cell and extracted after undergoing spin exchange with the Rb atoms. We compare the performance of the source when different buffer gases are used. We measure a decrease in electron polarization as their injection energy increases, but find an unexpected regime at higher injection energies yielding increased electron polarization accompanied by a 40-fold increase in current, suggesting the production of slow secondary electrons in the target cell. With ethylene, we have measured electron currents of 4 ?A simultaneously with electron polarizations of 24%. This work offers the promise of a simple, benchtop, “turnkey” source of polarized electrons.

M. Pirbhai; J. Knepper; E. T. Litaker; D. Tupa; T. J. Gay

2013-12-31T23:59:59.000Z

97

Polarized electron source for parity experiment at Bates  

SciTech Connect (OSTI)

We are constructing a polarized electron source in order to study parity violation in elastic electron-carbon scattering at the MIT Bates Linac. The source uses a GaAs photocathode illuminated by light from an infrared krypton ion laser. Our design, which uses a multi-chamber vacuum system, meets the special requirements for operation at Bates.

Souder, P.; Barber, A.; Bertozzi, W.

1981-01-01T23:59:59.000Z

98

Polarized electron source for parity experiment at bates  

SciTech Connect (OSTI)

The authors are constructing a polarized electron source in order to study parity violation in elastic electron-carbon scattering at the MIT Bates Linac. The source uses a GaAs photocathode illuminated by light from an infrared krypton ion laser. The design, which uses a multi-chamber vacuum system, meets the special requirements for operation at Bates. 12 references, 4 figures.

Souder, P.; Barber, A.; Bertozzi, W.; Cates, G.; Dodson, G.; Gay, T.J.; Goodman, M.; Hughes, V.W.; Kowalski, S.; Lubell, M.S.

1983-01-01T23:59:59.000Z

99

Project Execution Plan Electron Beam Ion Source Project  

E-Print Network [OSTI]

Project Execution Plan for the Electron Beam Ion Source Project (EBIS) Project # 07-SC-02 of Nuclear Physics (SC ­ 26) Rev. 1 May 2008 #12;#12;#12;4 Project Execution Plan for the Electron Beam Ion Source Project (EBIS) Change Log Revision No. Pages Affected Effective Date Revision 0 Baseline Document

100

Proposed dielectric-based microstructure laser-driven undulator T. Plettner and R. L. Byer  

E-Print Network [OSTI]

sources that feed into permanent-magnet undulators. The distinguish- ing feature of the undulator proposed to couple a laser beam into an accelerating force that remains overlapped with the relativistic electron

Byer, Robert L.

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Terahertz-driven linear electron acceleration  

E-Print Network [OSTI]

The cost, size and availability of electron accelerators is dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency (RF) accelerating structures operate with 30-50 MeV/m gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional RF structures. However, laser-driven electron accelerators require intense sources and suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here, we demonstrate the first linear acceleration of electrons with keV energy gain using optically-generated terahertz (THz) pulses. THz-driven accelerating structures enable high-gradient electron accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. Increasing the operational frequency of accelerators into the THz band allows for greatly increased accelerating ...

Nanni, Emilio Alessandro; Ravi, Koustuban; Fallahi, Arya; Moriena, Gustavo; Miller, R J Dwayne; Kärtner, Franz X

2014-01-01T23:59:59.000Z

102

Model Reduction for Power Electronics Systems with Multiple Heat Sources  

E-Print Network [OSTI]

Model Reduction for Power Electronics Systems with Multiple Heat Sources A. Augustin, T. Hauck, B demonstrates the model order re- duction procedures applied to semiconductor devices with multiple heat sources. The approach is demonstrated for a device with nine heat sources where some of them are perma- nently active

Paris-Sud XI, Université de

103

Electron beam welding of ceramic to metal using fore-vacuum plasma electron source  

Science Journals Connector (OSTI)

The possibility of creating ceramic-metal joints by electron beam welding is considered. The welding of ... range (5–20 Pa) using a plasma electron source. The structure and composition of the ceramic ... breakin...

A. K. Goreev; V. A. Burdovitsin; A. S. Klimov…

2012-09-01T23:59:59.000Z

104

Auger electron and photoelectron angular distributions from surfaces: Importance of the electron source wave  

Science Journals Connector (OSTI)

Angular distributions of Auger electrons and of photoelectrons emitted at high (>500 eV) and low (source wave strongly influences these patterns.

T. Greber; J. Osterwalder; D. Naumovi?; A. Stuck; S. Hüfner; L. Schlapbach

1992-09-28T23:59:59.000Z

105

Investigation of laser-driven proton acceleration using ultra-short, ultra-intense laser pulses  

SciTech Connect (OSTI)

We report optimization of laser-driven proton acceleration, for a range of experimental parameters available from a single ultrafast Ti:sapphire laser system. We have characterized laser-generated protons produced at the rear and front target surfaces of thin solid targets (15 nm to 90 {mu}m thicknesses) irradiated with an ultra-intense laser pulse (up to 10{sup 20} W Dot-Operator cm{sup -2}, pulse duration 30 to 500 fs, and pulse energy 0.1 to 1.8 J). We find an almost symmetric behaviour for protons accelerated from rear and front sides, and a linear scaling of proton energy cut-off with increasing pulse energy. At constant laser intensity, we observe that the proton cut-off energy increases with increasing laser pulse duration, then roughly constant for pulses longer than 300 fs. Finally, we demonstrate that there is an optimum target thickness and pulse duration.

Fourmaux, S.; Gnedyuk, S.; Lassonde, P.; Payeur, S.; Pepin, H.; Kieffer, J. C. [INRS-EMT, Universite du Quebec, 1650 Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); Buffechoux, S.; Albertazzi, B. [INRS-EMT, Universite du Quebec, 1650 Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); LULI, UMR 7605, CNRS - CEA - Universite Paris 6 - Ecole Polytechnique, 91128 Palaiseau (France); Capelli, D.; Antici, P. [LULI, UMR 7605, CNRS - CEA - Universite Paris 6 - Ecole Polytechnique, 91128 Palaiseau (France); Dipartimento SBAI, Sapienza, Universita di Roma, Via Scarpa 16, 00161 Roma (Italy); Levy, A.; Fuchs, J. [LULI, UMR 7605, CNRS - CEA - Universite Paris 6 - Ecole Polytechnique, 91128 Palaiseau (France); Lecherbourg, L.; Marjoribanks, R. S. [Department of Physics and Institute for Optical Sciences, University of Toronto, Toronto, Ontario M5S 1A7 (Canada)

2013-01-15T23:59:59.000Z

106

ILC Polarized Electron Source Design and R&D Program  

SciTech Connect (OSTI)

The R and D program for the ILC electron focuses on three areas. These are the source drive laser system, the electron gun and photo cathodes necessary to produce a highly polarized electron beam. Currently, the laser system and photo cathode development take place at SLAC's 'ILC Injector Test facility', which is an integrated lab (laser and gun) that allows the production of the electron beam and is equipped with a set of diagnostics, necessary to characterize the source performance. Development of the ILC electron gun takes place at Jefferson Lab, where advanced concepts and technologies for HV DC electron guns for polarized beams are being developed. The goal is to combine both efforts at one facility to demonstrate an electron beam with ILC specifications, which are electron beam charge and polarization as well as the cathode's lifetime. The source parameters are summarized in Table 1. The current schematic design of the ILC central complex is depicted in Figure 1. The electron and positron sources are located and laid out approximately symmetric on either side of the damping rings.

Brachmann, A.; Sheppard, J.; Zhou, F.; Poelker, M.; /SLAC

2012-04-06T23:59:59.000Z

107

Tunable, Nanoscale Free-Electron Source of Photons and Plasmons  

Science Journals Connector (OSTI)

The passage of a free-electron beam through a nano-hole in a periodically layered metal/dielectric structure creates a new type of tuneable, nanoscale radiation source, analogous to...

Adamo, G; MacDonald, K F; Zheludev, N I; Fu, Y H; Wang, C -m; Tsai, D P; García de Abajo, F J

108

Formation of longitudinal nonlinear structures in the electron cloud of an electron-string ion source  

SciTech Connect (OSTI)

Accumulation of oscillating electrons in an electron-string ion source is simulated by the particle-in-cell method. The electrons are accumulated in a long trap into which an electron beam is injected. It is shown that a chain of alternating phase holes and squeezed states forms in the trap. The dynamical features of such a longitudinal structure, such as the double-pulse waveform and strong high-frequency oscillations of the accumulation current and the broadening of the electron distribution function, are qualitatively similar to those previously observed in experiments with the Krion-2 ion source operating in the electron-string mode.

Donets, E. D.; Donets, E. E.; Syresin, E. M. [Joint Institute for Nuclear Research (Russian Federation); Dubinov, A. E.; Makarov, I. V.; Sadovoy, S. A.; Saikov, S. K. [Russian Federal Nuclear Center-All-Russia Research Institute of Experimental Physics (Russian Federation); Tarakanov, V. P. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2009-01-15T23:59:59.000Z

109

Electron-positron annihilation and hadronic sources  

Science Journals Connector (OSTI)

The canonical leading light-cone contribution ???+(x)p?f(x·p)+? to the electroproduction [?(q)+h(p)?anything;?=photon, h=hadron] matrix element ?h(p)|J?(x)J?(0)|h(p)? is such that f(?), by virtue of the J?J? operator-product expansion (OPE), is analytic for small ?. The corresponding contribution ???+(x)p?f¯(x·p)+? to the annihilation [e+e-??(q)?h(p)+anything] matrix element ?0|R(J?(x)S^(p))R(J?(x)S^†(-p))|0?, where S^(p) is the Fourier transform of a source operator S(y) for h(p), is such that f¯(?) can be singular for ??0; f¯(?)??-?. We show how the multiple OPE's among the operators involved can determine the degree ? of this short-distance singularity provided long-distance effects are not important. We refer to ? as the "slant" of the matrix element and we explicitly calculate ? in terms of the minimal dimension d of the source S(y). In the canonical case, we find ?=d-12 if h is a pseudoscalar particle and ?=d-1 if h is a spinor particle. These singularities imply that the scaling functions behave like ?? for ??q22q·p?? and that the multiplicities behave like (q2)?-3 for q2??. These results provide handles on the heretofore elusive source dimensions d. For example, if logarithmic or greater multiplicities are observed (??3) along with canonical scaling, it can be concluded that d cannot have its canonical elementary value (d=52 for spinors, d=3 for scalars) but rather d?72 (spinors) or d?4 (scalars). These results can be readily generalized to noncanonical cases. For example, they lead to simple explanations of known results in renormalized perturbation theory (?3 theory, ?4 theory, pseudoscalar-meson theory, quantum electrodynamics). Since ? (and ?) is dimensionless, the dimensional analysis involved in our treatment is on a different footing from that which determines the usual short-distance and light-cone singularities of current products. The slants are nevertheless simple functions of the field and source dimensions. Phenomenologically, the operatorial nature of our approach makes it easily extendable to the treatment of other inclusive lepton hadron processes with one or more particles observed in the final state.

Richard A. Brandt and Ng Wing-Chiu

1974-09-15T23:59:59.000Z

110

Investigation of noise sources in SQUID electronics  

SciTech Connect (OSTI)

The performance of SQUID-based electronics outside a laboratory-controlled environment may be degraded from that found in laboratory operation. Investigations on superconducting tubes, wires, and sheets have been conducted to identify contributions to such noise. Results have been obtained for bulk and thin film samples utilizing both the conventional low temperature materials, as well as the new high temperature oxide materials. Experiments have been conducted to quantify flux redistribution and flux motion in superconducting samples subjected to temperature changes, temperature gradients, and magnetic field gradients. These investigations have been conducted at magnetic fields typical of many SQUID applications, with field intensities much smaller than the critical values H/sub cl/. Penetration depth effects, flux pinning effects, and flux motion effects have been observed. The various types of experiments conducted along with specific results are described.

Clem, T.R.; Goldstein, M.J.; Purpura, J.W.; Allen, L.H.; Claassen, J.H.; Gubser, D.U.; Wolf, S.A.

1989-03-01T23:59:59.000Z

111

Multifunctional bulk plasma source based on discharge with electron injection  

SciTech Connect (OSTI)

A bulk plasma source, based on a high-current dc glow discharge with electron injection, is described. Electron injection and some special design features of the plasma arc emitter provide a plasma source with very long periods between maintenance down-times and a long overall lifetime. The source uses a sectioned sputter-electrode array with six individual sputter targets, each of which can be independently biased. This discharge assembly configuration provides multifunctional operation, including plasma generation from different gases (argon, nitrogen, oxygen, acetylene) and deposition of composite metal nitride and oxide coatings.

Klimov, A. S.; Medovnik, A. V. [Tomsk State University of Control Systems and Radioelectronics, Tomsk 634050 (Russian Federation); Tyunkov, A. V. [Tomsk State University of Control Systems and Radioelectronics, Tomsk 634050 (Russian Federation); Institute of High Current Electronics, Tomsk 634055 (Russian Federation); Savkin, K. P.; Shandrikov, M. V.; Vizir, A. V. [Institute of High Current Electronics, Tomsk 634055 (Russian Federation)

2013-01-15T23:59:59.000Z

112

Optical Performance of Carbon-Nanotube Electron Sources  

Science Journals Connector (OSTI)

The figure of merit for the electron optical performance of carbon-nanotube (CNT) electron sources is presented. This figure is given by the relation between the reduced brightness and the energy spread in the region of stable emission. It is shown experimentally that a CNT electron source exhibits a highly stable emission process that follows the Fowler-Nordheim theory for field emission, fixing the relationship among the energy spread, the current, and the radius. The performance of the CNT emitter under realistic operating conditions is compared with state-of-the-art electron point sources. It is demonstrated that the reduced brightness is a function of the tunneling parameter, a measure of the energy spread at low temperatures, only, independent of the geometry of the emitter.

Niels de Jonge; Myriam Allioux; Jim T. Oostveen; Kenneth B. K. Teo; William I. Milne

2005-05-11T23:59:59.000Z

113

Proposal for a Quantum-Degenerate Electron Source  

Science Journals Connector (OSTI)

We propose a pulsed electron source capable of 6D brightness orders-of-magnitude greater than that of existing sources. It could deliver average current up to 0.5 pA and achieve an emittance approaching the quantum limit in each spatial dimension. It could be employed to advantage in electron microscopy, inverse photo-emission, precision low-energy scattering experiments, and electron holography. This source could make possible pump-probe experiments with Ångstrom spatial and subpicosecond time resolution. Here, we present the basic concepts of the source, including a generalized expression for the brightness that can be used in the quantum limited case and the analysis of the main issues that must be addressed for successful construction and operation. We have begun an experiment to demonstrate its essential features.

M. Zolotorev; E. D. Commins; F. Sannibale

2007-05-03T23:59:59.000Z

114

An angular-selective electron source for the KATRIN experiment  

E-Print Network [OSTI]

The KATRIN experiment is going to search for the average mass of the electron antineutrino with a sensitivity of 0.2 eV/c2. It uses a retardation spectrometer of MAC-E filter type to accurately measure the shape of the electron spectrum at the endpoint of tritium beta decay. In order to achieve the planned sensitivity the transmission properties of the spectrometer have to be understood with high precision for all initial conditions. For this purpose an electron source has been developed that emits single electrons at adjustable total energy and adjustable emission angle. The emission is pointlike and can be moved across the full flux tube that is imaged onto the detector. Here, we demonstrate that this novel type of electron source can be used to investigate the transmission properties of a MAC-E filter in detail.

Beck, M; Hein, H; Bauer, S; Baumeister, H; Bonn, J; Ortjohann, H -W; Ostrick, B; Rosendahl, S; Streubel, S; Valerius, K; Zboril, M; Weinheimer, C

2014-01-01T23:59:59.000Z

115

Self-Referenced Single-Electron Quantized Current Source  

Science Journals Connector (OSTI)

The future redefinition of the international system of units in terms of natural constants requires a robust, high-precision quantum standard for the electrical base unit ampere. However, the reliability of any single-electron current source generating a nominally quantized output current I=ef by delivering single electrons with charge e at a frequency f is eventually limited by the stochastic nature of the underlying quantum mechanical tunneling process. We experimentally explore a path to overcome this fundamental limitation by serially connecting clocked single-electron emitters with multiple in situ single-electron detectors. Correlation analysis of the detector signatures during current generation reveals erroneous pumping events and enables us to determine the deviation of the output current from the nominal quantized value ef. This demonstrates the concept of a self-referenced single-electron source for electrical quantum metrology.

Lukas Fricke; Michael Wulf; Bernd Kaestner; Frank Hohls; Philipp Mirovsky; Brigitte Mackrodt; Ralf Dolata; Thomas Weimann; Klaus Pierz; Uwe Siegner; Hans W. Schumacher

2014-06-06T23:59:59.000Z

116

In-line electron holography with an atomic focuser source  

Science Journals Connector (OSTI)

The resolution that may be achieved in an image formed by reconstruction from an in-line electron hologram, without aberration correction, is governed by the source size. Computer simulations show that ultrahigh resolution, of better than 0.05 nm for 100 keV electrons, may be possible if the electron source is a crossover formed at the exit face of a thin atomic-focuser crystal when electrons from a beam focused in a scanning transmission electron microscope (STEM) instrument are channeled along a line of atoms through the crystal. Simulations also show that, because of the channeling effect, the resolution of the reconstructed image is not degraded by translations or oscillations of the STEM beam by 0.1 nm or more. We suggest a scheme for removing the unwanted background and conjugate image from the reconstructed image by combining the in-line holography with an off-axis mode.

V. V. Smirnov and J. M. Cowley

2002-01-23T23:59:59.000Z

117

Development of a High-Brightness VHF Electron Source at LBNL  

E-Print Network [OSTI]

A HIGH-BRIGHTNESS VHF ELECTRON SOURCE AT LBNL* S. Lidia # ,design for a 750kV electron source and beam injection systemFEL projects require electron beam sources that can generate

Lidia, Steven M.; Sannibale, Fernando; Staples, John W.; Virostek, Steve P.; Wells, Russell P.

2008-01-01T23:59:59.000Z

118

Measurements of plasma bremsstrahlung and plasma energy density produced by electron cyclotron resonance ion source plasmas  

E-Print Network [OSTI]

Studies of electron heating on a 6.4 GHz ECR ion source 3.114 GHz Advanced Electron Cyclotron Source-Upgraded (AECR-U).spectra in electron cyclotron resonance ion source plasmas,”

Noland, Jonathan David

2011-01-01T23:59:59.000Z

119

Study of a liquid metal ion source for external ion injection into electron-beam ion source  

E-Print Network [OSTI]

Study of a liquid metal ion source for external ion injection into electron-beam ion source A into electron-beam ion source EBIS . It does not use a buffer gas and therefore it provides only a very small types of low-charged ion sources have been used for external ion injection into BNL electron-beam ion

120

Novel free-form hohlraum shape design and optimization for laser-driven inertial confinement fusion  

SciTech Connect (OSTI)

The hohlraum shape attracts considerable attention because there is no successful ignition method for laser-driven inertial confinement fusion at the National Ignition Facility. The available hohlraums are typically designed with simple conic curves, including ellipses, parabolas, arcs, or Lame curves, which allow only a few design parameters for the shape optimization, making it difficult to improve the performance, e.g., the energy coupling efficiency or radiation drive symmetry. A novel free-form hohlraum design and optimization approach based on the non-uniform rational basis spline (NURBS) model is proposed. In the present study, (1) all kinds of hohlraum shapes can be uniformly represented using NURBS, which is greatly beneficial for obtaining the optimal available hohlraum shapes, and (2) such free-form uniform representation enables us to obtain an optimal shape over a large design domain for the hohlraum with a more uniform radiation and higher drive temperature of the fuel capsule. Finally, a hohlraum is optimized and evaluated with respect to the drive temperature and symmetry at the Shenguang III laser facility in China. The drive temperature and symmetry results indicate that such a free-form representation is advantageous over available hohlraum shapes because it can substantially expand the shape design domain so as to obtain an optimal hohlraum with high performance.

Jiang, Shaoen; Jing, Longfei, E-mail: scmyking-2008@163.com; Ding, Yongkun [Laser Fusion Research Center, China Academy Engineering Physics, Mianyang 621900 (China); Huang, Yunbao, E-mail: huangyblhy@gmail.com [Mechatronics School of Guangdong University of Technology, Guangzhou 510006 (China)

2014-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

41.8-nm Xe8+ laser driven in a plasma waveguide  

Science Journals Connector (OSTI)

An experimental demonstration of an optical field ionization short-wavelength laser driven in a gas-filled capillary-discharge waveguide is described in detail. Guiding of high-intensity laser pulses has previously been demonstrated with this type of waveguide for capillary discharges in hydrogen. For the present experiments xenon gas was mixed with the hydrogen, and strong lasing on the 4d95d-4d95p transition in Xe8+ at 41.8nm was observed. Under optimum conditions the short-wavelength laser output achieved with the waveguide was found to be greater than that from a Xe gas cell. Measurements of the transmission of the pump laser pulses through the waveguide show that the short-wavelength laser signal was greatest under conditions for which the pump laser pulses were well guided. Simulations of the propagation of the pump laser radiation are presented for a range of initial plasma conditions, and these indicate that the laser-plasma interaction length achieved was greatly increased compared to that which can be achieved in a gas cell.

A. Butler; A. J. Gonsalves; C. M. McKenna; D. J. Spence; S. M. Hooker; S. Sebban; T. Mocek; I. Betttaibi; B. Cros

2004-08-30T23:59:59.000Z

122

Spatial coherence of electron bunches extracted from an arbitrarily shaped cold atom electron source  

Science Journals Connector (OSTI)

We describe the spatial coherence properties of a cold atom electron source in the framework of a quasihomogeneous wavefield. The model is used as the basis for direct measurements of...

Saliba, Sebastian D; Putkunz, Corey T; Sheludko, David V; McCulloch, Andrew J; Nugent, Keith A; Scholten, Robert E

2012-01-01T23:59:59.000Z

123

Risk Management Plan Electron Beam Ion Source Project  

E-Print Network [OSTI]

, with the appropriate management oversight, can establish the specific approaches to addressing the individual riskRisk Management Plan for the Electron Beam Ion Source Project (EBIS) Project # 06-SC-002 at Brookhaven National Laboratory Upton, NY For the U.S. Department of Energy Office of Science Office

124

Optimal electron entangler and single-electron source at low temperatures  

Science Journals Connector (OSTI)

We show that the equilibrium noise can be dramatically suppressed in the case of a tunnel junction with modulated (time-dependent) transparency. We demonstrate how such a contact could be used either as an optimal electron entangler or as a single-electron source with suppressed equilibrium noise at low temperatures.

Y. Sherkunov; Jin Zhang; N. d’Ambrumenil; B. Muzykantskii

2009-07-29T23:59:59.000Z

125

On the electron-electron interaction as the source of the metallic resistivity in TTF-TCNQ  

Science Journals Connector (OSTI)

The source of the metallic resistivity in TTF-TCNQ ... will consider in detail the possibility that the electron-electron interaction is responsible for the resistivity in...

P. E. Seiden; P. M. Grant

1979-01-01T23:59:59.000Z

126

E-Print Network 3.0 - accelerated electrons degradacion Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Tsinghua University, Hsinchu, Taiwan 30043. Summary: for a laser-driven electron accelerator Y.C. Huang *, T. Plettner , R.L. Byer , R.H. Pantell , R.L. Swent , T... for...

127

A compact x-ray free electron laser  

SciTech Connect (OSTI)

We present a design concept and simulation of the performance of a compact x-ray, free electron laser driven by ultra-high gradient rf-linacs. The accelerator design is based on recent advances in high gradient technology by a LLNL/SLAC/LBL collaboration and on the development of bright, high current electron sources by BNL and LANL. The GeV electron beams generated with such accelerators can be converted to soft x-rays in the range from 2--10 nm by passage through short period, high field strength wigglers as are being designed at Rocketdyne Linear light sources of this type can produce trains of picosecond (or shorter) pulses of extremely high spectral brilliance suitablee for flash holography of biological specimens in vivo and for studies of fast chemical reactions. 12 refs., 8 figs., 4 tabs.

Barletta, W.A. (California Univ., Los Angeles, CA (USA). Center for Advanced Accelerators Physics Lawrence Livermore National Lab., CA (USA)); Atac, M.; Cline, D.B.; Kolonko, J. (California Univ., Los Angeles, CA (USA). Center for Advanced Accelerators Physics); Bhowmik, A.; Bobbs, B.; Cover, R.A.; Dixon, F.P.; Rakowsky, G. (Rockwell International Corp., Canoga Park, CA (USA). Rocketdyne Div.); Gallardo

1988-01-01T23:59:59.000Z

128

A compact x-ray free electron laser  

SciTech Connect (OSTI)

We present a design concept and simulation of the performance of a compact x-ray, free electron laser driven by ultra-high gradient rf-linacs. The accelerator design is based on recent advances in high gradient technology by a LLNL/SLAC/LBL collaboration and on the development of bright, high current electron sources by BNL and LANL. The GeV electron beams generated with such accelerators can be concerted to soft x-rays in the range from 2--10 nm by passage through short period, high fields strength wigglers as are being designed at Rocketdyne. Linear light sources of this type can produce trains of picosecond (or shorter) pulses of extremely high spectral brilliance suitable for flash holography of biological specimens in vivo and for studies of fast chemical reactions. 12 refs., 8 figs., 4 tabs.

Barletta, W.; Attac, M.; Cline, D.B.; Kolonko, J.; Wang, X.; Bhowmik, A.; Bobbs, B.; Cover, R.A.; Dixon, F.P.; Rakowsky, G.; Gallardo, J.; Pellegrini, C.; Westenskow, G.

1988-09-09T23:59:59.000Z

129

Plasma modeling in an electron-cyclotron-resonance ion source  

Science Journals Connector (OSTI)

Modeling calculations of an electron-cyclotron-resonance ion source (ECRIS) are presented. The adopted model is described through an analysis of the impact of ECR heating, transport, and atomic-collision processes on the particle balance in an ECRIS. On the basis of the obtained numerical results, general relationships among externally controllable parameters, and plasma and ion-beam characteristics are derived. Comparison with experimental results that use the electron energy as the only fitting parameter supports the applied model. The predicted general trends provide some basis for future experiments.

S. Pei? and M. Vukovi?

1990-09-15T23:59:59.000Z

130

Laser ion source with solenoid for Brookhaven National Laboratory-electron beam ion source  

SciTech Connect (OSTI)

The electron beam ion source (EBIS) preinjector at Brookhaven National Laboratory (BNL) is a new heavy ion-preinjector for relativistic heavy ion collider (RHIC) and NASA Space Radiation Laboratory (NSRL). Laser ion source (LIS) is a primary ion source provider for the BNL-EBIS. LIS with solenoid at the plasma drift section can realize the low peak current ({approx}100 {mu}A) with high charge ({approx}10 nC) which is the BNL-EBIS requirement. The gap between two solenoids does not cause serious plasma current decay, which helps us to make up the BNL-EBIS beamline.

Kondo, K.; Okamura, M. [Collider-Accelerator Department, Brookhaven National Laboratory, New York (United States); Yamamoto, T. [Cooperative Major in Nuclear Energy, Waseda University, Tokyo (Japan); Sekine, M. [Department of Nuclear Engineering, Tokyo Institute of Technology, Tokyo (Japan)

2012-02-15T23:59:59.000Z

131

Laser ion source with solenoid for Brookhaven National Laboratory-electron beam ion source  

SciTech Connect (OSTI)

The electron beam ion source (EBIS) preinjector at Brookhaven National Laboratory (BNL) is a new heavy ion-preinjector for relativistic heavy ion collider (RHIC) and NASA Space Radiation Laboratory (NSRL). Laser ion source (LIS) is a primary ion source provider for the BNL-EBIS. LIS with solenoid at the plasma drift section can realize the low peak current ({approx}100 {micro}A) with high charge ({approx}10 nC) which is the BNL-EBIS requirement. The gap between two solenoids does not cause serious plasma current decay, which helps us to make up the BNL-EBIS beamline.

Kondo K.; Yamamoto, T.; Sekine, M.; Okamura, M.

2012-02-22T23:59:59.000Z

132

Inverse free electron laser accelerator for advanced light sources  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

We discuss the inverse free electron laser (IFEL) scheme as a compact high gradient accelerator solution for driving advanced light sources such as a soft x-ray free electron laser amplifier or an inverse Compton scattering based gamma-ray source. In particular, we present a series of new developments aimed at improving the design of future IFEL accelerators. These include a new procedure to optimize the choice of the undulator tapering, a new concept for prebunching which greatly improves the fraction of trapped particles and the final energy spread, and a self-consistent study of beam loading effects which leads to an energy-efficient high laser-to-beam power conversion.

Duris, J. P.; Musumeci, P.; Li, R. K.

2012-06-01T23:59:59.000Z

133

RF Heating in Electron Cyclotron Resonance Ion Sources  

SciTech Connect (OSTI)

ECRIS-Electron Cyclotron Resonance Ion Sources are able to feed accelerators with intense currents of highly charged ions. In ECRIS a high density-high temperature plasma is generated by means of the Electron Cyclotron Resonance Heating inside a B-min, MHD stable trap. The state of the art about the principal heating mechanisms will be given. The paper will specially discuss the most critical and still open issues concerning the influence of the magnetic field and of the RF frequency on the plasma heating, as well as the impact of possible non-linear pumping wave-to-plasma interactions. The contribution of INFN-LNS will be specifically underlined. A short review on the future perspectives for the design of new generation ion sources will be given in conclusion.

Mascali, D. [INFN - LNS, via S. Sofia 62, 95123 Catania (Italy); CSFNSM, Viale A. Doria, 6 - 95125 Catania (Italy); Gammino, S.; Celona, L.; Ciavola, G. [INFN - LNS, via S. Sofia 62, 95123 Catania (Italy)

2011-12-23T23:59:59.000Z

134

Beam-dynamics Simulations for Channeling Radiation Electron Source  

Science Journals Connector (OSTI)

Abstract The intensity and the brilliance of the compact X-ray sources based on channeling radiation are strongly dependant on the electron beam quality. It was recently proposed to combine a field-emission electron source with channeling radiation through a diamond crystal to produce high-spectral-brilliance X-rays. There are two experiments in preparation at Fermilab to prove this technique. The beam energy in the two cases are 5-MeV and 40-MeV respectively. The field-emitted beams have emittance in the nanometer range when the microbunch is 25 ps long and the charge is about 2.5fC. RF guns operating at 1.3 GHz can produce trains of at least 2 × 105 microbunches. In this contribution we present beam-dymamics simulations of a the field-emission and subsequent accelerator up to the channeling-radiation target.

D. Mihalcea; C.A. Brau; B.K. Choi; W. Gabella; J.D. Jarvis; J.W. Lewellen; M. Mendenhall; P. Piot

2014-01-01T23:59:59.000Z

135

Fabrication of gated nano electron source for vacuum nanoelectronics  

Science Journals Connector (OSTI)

Abstract Many kinds of attractive new applications, such as image sensors, stationary X-ray sources, and the column-less SEM, are investigated as post field emission displays that use a gated nano electron source. The fabrication of the gated nano electron source is overviewed from the conventional method to the latest one, especially in regarding to the gate formation process. Multi-stacked gate electrode formation using an etch-back method was developed recently, which is a very attractive method for generating a focused electron beam. The traditional Spindt-type emitter fabrication method is also being improved to the one that is easier and applicable to large area substrates. Using a double-layered photoresist as a lift-off layer and using HiPIMS sputtering instead of an e-beam evaporator was proposed. Thin film-type FEA fabrication is also improved to make vertically standing thin film by ion irradiation, which is applicable for making an emitter array on a large sized substrate.

Masayoshi Nagao; Tomoya Yoshida

2015-01-01T23:59:59.000Z

136

Electron Cloud Mitigation in the Spallation Neutron Source Ring  

SciTech Connect (OSTI)

The Spallation Neutron Source (SNS) accumulator ring is designed to accumulate, via H{sup -} injection, protons of 2 MW beam power at 1 GeV kinetic energy at a repetition rate of 60 Hz [1]. At such beam intensity, electron-cloud is expected to be one of the intensity-limiting mechanisms that complicate ring operations. This paper summarizes mitigation strategy adopted in the design, both in suppressing electron-cloud formation and in enhancing Landau damping, including tapered magnetic field and monitoring system for the collection of stripped electrons at injection, TiN coated beam chamber for suppression of the secondary yield, clearing electrodes dedicated for the injection region and parasitic on BPMs around the ring, solenoid windings in the collimation region, and planning of vacuum systems for beam scrubbing upon operation.

Wei, J.; Blaskiewicz, Michael; Brodowski, J.; Cameron, P.; Davino, Daniele; Fedotov, A.; He, P.; Hseuh, H.; Lee, Y.Y.; Ludewig, H.; Meng, W.; Raparia, D.; Tuozzolo, J.; Zhang, S.Y.; Catalan-Lasheras, N.; Macek, R.J.; Furman, Miguel A.; Aleksandrov, A.; Cousineau, S.; Danilov, V.; Henderson, S.; /Brookhaven /CERN /LANL, Ctr. for Nonlinear Studies /LBL, Berkeley /Oak Ridge /SLAC

2008-03-17T23:59:59.000Z

137

ELECTRON STRING SOURCE OF HIGHLY CHARGED IONS: STUDIES AND THE FIRST TEST ON A SYNCHROTRON  

E-Print Network [OSTI]

ELECTRON STRING SOURCE OF HIGHLY CHARGED IONS: STUDIES AND THE FIRST TEST ON A SYNCHROTRON E. D, MSL, 104 05 Stockholm, Sweden Abstract Operation of an electron beam ion source (EBIS) in the reflex in Electron String Ion Source (ESIS). We describe the experiments and results on studies of electron string

138

Highly Polarized Ion Sources for Electron Ion Colliders (EIC)  

SciTech Connect (OSTI)

The operation of the RHIC facility at BNL and the Electron Ion Colliders (EIC) under development at Jefferson Laboratory and BNL need high brightness ion beams with the highest polarization. Charge exchange injection into a storage ring or synchrotron and Siberian snakes have the potential to handle the needed polarized beam currents, but first the ion sources must create beams with the highest possible polarization to maximize collider productivity, which is proportional to a high power of the polarization. We are developing one universal H-/D- ion source design which will synthesize the most advanced developments in the field of polarized ion sources to provide high current, high brightness, ion beams with greater than 90% polarization, good lifetime, high reliability, and good power efficiency. The new source will be an advanced version of an atomic beam polarized ion source (ABPIS) with resonant charge exchange ionization by negative ions. An integrated ABPIS design will be prepared based on new materials and an optimized magnetic focusing system. Polarized atomic and ion beam formation, extraction, and transport for the new source will be computer simulated.

V.G. Dudnikov, R.P. Johnson, Y.S. Derbenev, Y. Zhang

2010-03-01T23:59:59.000Z

139

A Nanometer-sized Femtosecond Electron Source at 80 MHz Repetition Rate  

Science Journals Connector (OSTI)

We observe multiphoton electron emission from ultrasharp metallic tips illuminated with ... tip apex, demonstrating the potential of this source for ultrafast electron imaging with nanometer-resolution.

Claus Ropers; Daniel R. Solli; Claus Peter Schulz…

2007-01-01T23:59:59.000Z

140

Electron source for a mini ion trap mass spectrometer  

DOE Patents [OSTI]

An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

Dietrich, D.D.; Keville, R.F.

1995-12-19T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Electron source for a mini ion trap mass spectrometer  

DOE Patents [OSTI]

An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

Dietrich, Daniel D. (Livermore, CA); Keville, Robert F. (Valley Springs, CA)

1995-01-01T23:59:59.000Z

142

Theoretical investigation of a tunable free-electron light source  

SciTech Connect (OSTI)

The concept and experimental results of a light source given in a recent paper by Adamo et al.[Phys. Rev. Lett. 103, 113901 (2009)] are very interesting and attractive. Our paper presents detailed theoretical investigations on such a light source, and our results confirm that the mechanism of the light radiation experimentally detected in the published paper is a special kind of diffraction radiation in a waveguide with nanoscale periodic structure excited by an electron beam. The numerical calculations based on our theory and digital simulations agree well with the experimental results. This mechanism of diffraction radiation is of significance in physics and optics, and may bring good opportunities for the generation of electromagnetic waves from terahertz to light frequency regimes.

Liu Shenggang; Hu Min; Zhang Yaxin; Liu Weihao; Zhang Ping; Zhou Jun [Terahertz Research Center, University of Electronic Science and Technology of China, Chengdu 610054 (China)

2011-06-15T23:59:59.000Z

143

Theoretical investigation of a tunable free-electron light source  

Science Journals Connector (OSTI)

The concept and experimental results of a light source given in a recent paper by Adamo et al. [Phys. Rev. Lett. 103, 113901 (2009)] are very interesting and attractive. Our paper presents detailed theoretical investigations on such a light source, and our results confirm that the mechanism of the light radiation experimentally detected in the published paper is a special kind of diffraction radiation in a waveguide with nanoscale periodic structure excited by an electron beam. The numerical calculations based on our theory and digital simulations agree well with the experimental results. This mechanism of diffraction radiation is of significance in physics and optics, and may bring good opportunities for the generation of electromagnetic waves from terahertz to light frequency regimes.

Shenggang Liu; Min Hu; Yaxin Zhang; Weihao Liu; Ping Zhang; Jun Zhou

2011-06-30T23:59:59.000Z

144

Operating experience with a GaAs photoemission electron source  

SciTech Connect (OSTI)

We report on the development of several operating procedures that promise to make GaAs photoemission electron sources easier to construct, more reliable to operate, and more amenable to use in dynamic vacuum systems. We describe in particular a method for ''ohmically'' heating a <100> crystal of GaAs under vacuum to approximately 600 /sup 0/C. We also discuss our observations of the role of oxygen in the activation of the crystal surface, the use of continuous cesiation, and of the performance of the crystal under varying vacuum conditions.

Tang, F.C.; Lubell, M.S.; Rubin, K.; Vasilakis, A.; Eminyan, M.; Slevin, J.

1986-12-01T23:59:59.000Z

145

BNL-73700-2005-IR ELECTRON BEAM ION SOURCE PRE-INJECTOR PROJECT  

E-Print Network [OSTI]

BNL-73700-2005-IR ELECTRON BEAM ION SOURCE PRE-INJECTOR PROJECT (EBIS) CONCEPTUAL DESIGN REPORT J.2. THE EBIS SOURCE .........................................................................................14 4.2. DEMONSTRATION OF HIGH CURRENT ELECTRON BEAM FORMATION AND PROPAGATION

146

Electric strength of the accelerating gap of a plasma electron source at rough vacuum  

Science Journals Connector (OSTI)

Conditions for the electric breakdown of the accelerating gap of a plasma electron source are determined. It is shown that,...

V. A. Burdovitsin; M. N. Kuzemchenko; E. M. Oks

2002-07-01T23:59:59.000Z

147

Auroral electron distributions within and close to the Saturn kilometric radiation source region  

E-Print Network [OSTI]

Auroral electron distributions within and close to the Saturn kilometric radiation source region P al. (2011), Auroral electron distributions within and close to the Saturn kilometric radiation source the electron cyclotron frequency, consistent with in situ observations of the SKR source region [Lamy et al

Gurnett, Donald A.

148

Photocathode source for studying two-dimensional fluid phenomena with magnetized electron columns  

E-Print Network [OSTI]

Photocathode source for studying two-dimensional fluid phenomena with magnetized electron columns D have been generated with thermionic sources, typically limiting the initial electron distribution a new electron source based on a cesium antimonide photocathode that can generate more complicated

Fajans, Joel

149

Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles  

Science Journals Connector (OSTI)

Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles ... Comment on “Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles” ... Comment on “Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles” ...

Toshiyuki Abe; Eiji Suzuki; Kentaro Nagoshi; Kohichi Miyashita; Masao Kaneko:

2000-03-24T23:59:59.000Z

150

A Plasma-Cathode Electron Source for Ribbon-Beam Generation at Forevacuum Pressures  

Science Journals Connector (OSTI)

A plasma electron source producing a ribbon beam at pressures of ... cathode is used as a plasma generator. Electrons are extracted through the emission slit in ... covered by a metal mesh. The maximum electron-b...

V. A. Burdovitsin; Yu. A. Burachevskii…

2003-03-01T23:59:59.000Z

151

Limits to Electron Beam Emittance from Stochastic Coulomb Interactions  

SciTech Connect (OSTI)

Dense electron beams can now be generated on an ultrafast timescale using laser driven photo-cathodes and these are used for a range of applications from ultrafast electron defraction to free electron lasers. Here we determine a lower bound to the emittance of an electron beam limited by fundamental stochastic Coulomb interactions.

Coleman-Smith, Christopher; Padmore, Howard A.; Wan, Weishi

2008-08-22T23:59:59.000Z

152

Experimental study of electron-and ion-beam properties on the BNL electron-beam ion source and comparison with theoretical models  

E-Print Network [OSTI]

Experimental study of electron- and ion-beam properties on the BNL electron-beam ion source of the BNL Test electron-beam ion source EBIS has been measured for different electron-beam currents With high electron current operation up to 10 A the BNL Test electron-beam ion source EBIS has demonstrated

153

Purification, Recovery, and Laser-Driven Fluorination of Silicon from Dissolved and Particulate Silica for the Measurement of Natural Stable Isotope Abundances  

Science Journals Connector (OSTI)

Purification, Recovery, and Laser-Driven Fluorination of Silicon from Dissolved and Particulate Silica for the Measurement of Natural Stable Isotope Abundances ... At least three simple techniques exist for this:? fusion of SiO2 with Na2CO3 to form water-soluble sodium silicate, dissolution in HF, or dissolution in NaOH. ...

Christina L. De La Rocha; Mark A. Brzezinski; Michael J. DeNiro

1996-11-01T23:59:59.000Z

154

Application of a Nonradioactive Pulsed Electron Source for Ion Mobility Spectrometry  

Science Journals Connector (OSTI)

The concept of the new electron source used here is based on the early work (1894) of P. Lenard who showed that electrons, generated in an electrical discharge tube, could pass through a thin aluminum foil. ... In contrast to radioactive sources which constantly produce free electrons, this nonradioactive source allows for the introduction of delay times between the ion formation process and the ion extraction in which no free electrons are being produced. ...

Frank Gunzer; Stefan Zimmermann; Wolfgang Baether

2010-03-30T23:59:59.000Z

155

A polarized look at nucleons: Laser electron gamma source  

SciTech Connect (OSTI)

As the title suggests we are going to look at reactions induced on nucleons by polarized photons. The results I am going to show today are from the Laser Electron Gamma Source, or LEGS'' facility, at Brookhaven National Laboratory. At LEGS, gamma ray beams are produced by backscattering laser light from relativistic electrons. I will only summarize the main characteristics of this facility, and leave an in depth description to Dr. Schaerf who will discuss LEGS and other similar backscattering facilities on Wednesday. Reactions with polarized photons inevitably reflect interference terms that for the most part remain hidden in spin-averaged unpolarized measurements. This provides a tool for probing interactions that depend upon spin. In particular, we are going to look today at two cases where the polarization is used to probe the tensor interaction. First, we will examine the tensor force between a proton-neutron pair in deuterium. Secondly, we will examine the tensor force between quarks in a proton that produces a small E2 component that is mixed with the predominantly M1 excitation of the delta resonance.The magnitude of this E2 components provides a sensitive probe of the structure of the Nucleon.

Not Available

1991-01-01T23:59:59.000Z

156

A Parametric Study of Electron Extraction from a Low Frequency Inductively Coupled RF-Plasma Source  

E-Print Network [OSTI]

: The electron extraction from a low-frequency (2 MHz) inductively-coupled rf-plasma cathode is characterizedA Parametric Study of Electron Extraction from a Low Frequency Inductively Coupled RF-Plasma Source and rf-plasma source, rf-power and xenon gas flow. The results demonstrate that the electron supply from

157

CONTROLS AND DIAGNOSTICS FOR THE HIGH CURRENT ELECTRON BEAM ION SOURCE AT BNL *  

E-Print Network [OSTI]

CONTROLS AND DIAGNOSTICS FOR THE HIGH CURRENT ELECTRON BEAM ION SOURCE AT BNL * E. Beebe, J Test Stand (EBTS), is a full electron beam power, half ion trap length prototype for an Electron Beam Ion Source (EBIS) that could meet requirements for the Relativistic Heavy Ion Collider (RHIC

158

Are energetic electrons in the solar wind the source of the outer radiation belt?  

E-Print Network [OSTI]

Are energetic electrons in the solar wind the source of the outer radiation belt? Xinlin Li,1 D. N in the solar wind are the source of the outer rela- tivistic electron radiation belt. Though there is some the correlation of en- ergetic electrons in the 20-200 keV range in the solar wind and of high speed solar wind

Li, Xinlin

159

Electron Microscopy of Myosin Molecules from Muscle and Non-Muscle Sources  

Science Journals Connector (OSTI)

...1976 research-article Electron Microscopy of Myosin...Muscle and Non-Muscle Sources A. Elliott G. Offer...give the two heads). Electron microscopy of myosin...muscle and non-muscle sources. | Journal Article...Chickens Microscopy, Electron Muscle Proteins Myosins...

1976-01-01T23:59:59.000Z

160

A fluid description for the discharge equilibrium of a divergent electron cyclotron resonance plasma source  

E-Print Network [OSTI]

of an ECR plasma source. The calculated global relationships between ( 1) the electron temperature. INTRODUCTION Since the introduction of microwave plasma sources that make use of electron cyclotron resonanceA fluid description for the discharge equilibrium of a divergent electron cyclotron resonance

Mauel, Michael E.

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Consequences of mode structure on plasma properties in electron cyclotron resonance sources  

E-Print Network [OSTI]

Consequences of mode structure on plasma properties in electron cyclotron resonance sources Ronald pressures, electron cyclotron resonance ECR sources are being developed for downstream etching, Urbana, Illinois 61801 Received 29 January 1999; accepted 21 May 1999 Low pressure 50 mTorr electron

Kushner, Mark

162

A parametric study of the source rate for outer radiation belt electrons using a Kalman filter  

E-Print Network [OSTI]

A parametric study of the source rate for outer radiation belt electrons using a Kalman filter Q), A parametric study of the source rate for outer radiation belt electrons using a Kalman filter, J. Geophys. Res increasingly popular to describe the outer radiation belt energetic electron environment. We use a Kalman

Li, Xinlin

163

Prospects for advanced electron cyclotron resonance and electron beam ion source charge breeding methods for EURISOL  

SciTech Connect (OSTI)

As the most ambitious concept of isotope separation on line (ISOL) facility, EURISOL aims at producing unprecedented intensities of post-accelerated radioactive isotopes. Charge breeding, which transforms the charge state of radioactive beams from 1+ to an n+ charge state prior to post-acceleration, is a key technology which has to overcome the following challenges: high charge states for high energies, efficiency, rapidity and purity. On the roadmap to EURISOL, a dedicated R and D is being undertaken to push forward the frontiers of the present state-of-the-art techniques which use either electron cyclotron resonance or electron beam ion sources. We describe here the guidelines of this R and D.

Delahaye, P.; Jardin, P.; Maunoury, L.; Traykov, E.; Varenne, F. [GANIL, CEA/DSM-CNRS/IN2P3, Bd. Becquerel, BP 55027, 14076 Caen Cedex 05 (France); Galata, A.; Porcellato, A. M.; Prete, G. F. [INFN-Laboratori Nazionali di Legnaro, Viale dell'Universita 2, 35020 Legnaro, Padova (Italy); Angot, J.; Lamy, T.; Sortais, P.; Thuillier, T. [LPSC Grenoble, 53, rue des Martyrs, 38026 Grenoble Cedex (France); Ban, G. [LPC Caen, 6 bd Marechal Juin, 14050 Caen Cedex (France); Celona, L.; Lunney, D. [INFN-Laboratori Nazionali del Sud, via S.Sofia 62, 95125 Catania (Italy); Choinski, J.; Gmaj, P.; Jakubowski, A.; Steckiewicz, O. [Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5a, 02 093 Warsaw (Poland); Kalvas, T. [Department of Physics, University of Jyvaeskylae, PB 35 (YFL) 40351 Jyvaeskylae (Finland); and others

2012-02-15T23:59:59.000Z

164

Laser Electron Gamma Source: Biennial progress report, June 1996  

SciTech Connect (OSTI)

The LEGS facility provides intense, polarized, monochromatic {gamma}-ray beams by Compton backscattering laser light from relativistic electrons circulating in the X-Ray storage ring of the National Synchrotron Light Source at Brookhaven national Laboratory. Since 1990, experiments have concentrated on single polarization observables (polarized beams on unpolarized targets) in nuclear reactions involving the {Delta} resonance. Highlights of the last two years are given. An updated status of LEGS, and recent publications, is available on the WWW via http://WWW.LEGS.BNL.GOV/{approximately}LEGS/. In 1997 a new phase of operations will begin, focusing on double-polarization measurements with circularly polarized photon beams and longitudinally polarized nucleon targets. This work requires the development of (i) a new frozen-spin hydrogen-deuteride target that provides high polarizations for both nuclear species, and (ii) a new large acceptance detector array for measuring total reaction cross sections in both neutral and charged-particle channels. Progress on these instrumentation developments is an ongoing effort of the LEGS Spin Collaboration (LSC) and is discussed in the last section of this report.

Sandorfi, A.M. [ed.

1996-09-01T23:59:59.000Z

165

High-voltage pulsed discharge in an electron source with a plasma cathode  

Science Journals Connector (OSTI)

The nature of and mechanism for producing a high-voltage discharge in an electron source with a plasma cathode are investigated. The possibility of generating pulsed electron currents with an amplitude of 103–104

S. P. Bugaev; F. Ya. Zagulov

1973-10-01T23:59:59.000Z

166

Electron and positron impact experiments on metallic foils at the giessen positron source TEPOS  

Science Journals Connector (OSTI)

The sources TEPOS for slow positrons were installed at the Giessen 65 MeV electron linear accelerator. Ratios of K- and L-shell ionization cross-sections by electron and positron impact were measured on Au-...?)/...

W. Faust; C. Hahn; M. Rückert; H. Schneider…

1991-01-01T23:59:59.000Z

167

Electron and positron impact experiments on metallic foils at the giessen positron source TEPOS  

Science Journals Connector (OSTI)

The sources TEPOS for slow positrons were installed at the Giessen 65 MeV electron linear accelerator. Ratios of K- and L-shell ionization cross-sections by electron and positron impact were measured on Au-...-)/...

W. Faust; C. Hahn; M. Rückert; H. Schneider…

1991-01-01T23:59:59.000Z

168

Heating Mechanisms in Short-Pulse Laser-Driven Cone Targets  

Science Journals Connector (OSTI)

The fast ignitor is a modern approach to laser fusion that uses a short-pulse laser to initiate thermonuclear burn. In its simplest form the laser launches relativistic electrons that carry its energy to a precompressed fusion target. Cones have been used to give the light access to the dense target core through the low-density ablative cloud surrounding it. Here the ANTHEM implicit hybrid simulation model shows that the peak ion temperatures measured in recent cone target experiments arose chiefly from return current joule heating, mildly supplemented by relativistic electron drag. Magnetic fields augment this heating only slightly, but capture hot electrons near the cone surface and force the hot electron stream into filaments.

R. J. Mason

2006-01-23T23:59:59.000Z

169

Coherence of single-electron sources from Mach-Zehnder interferometry  

Science Journals Connector (OSTI)

A unique type of electron source has emerged which permits to inject particles in a controllable manner, one at a time, into an electronic circuit. Such single-electron sources make it possible to address experimentally one of the most fundamental quantum properties of an electron, its coherence length. We propose a methodology to measure the single-particle coherence length from the decay of the Aharonov-Bohm oscillations as a function of the imbalance of a Mach-Zehnder interferometer.

Géraldine Haack; Michael Moskalets; Janine Splettstoesser; Markus Büttiker

2011-08-17T23:59:59.000Z

170

A novel non-radioactive electron source for ion mobility spectrometry  

Science Journals Connector (OSTI)

Typical ion mobility spectrometers work by employing a radioactive source to provide electrons with high energy to ionize the analytes ... resulted in a need for a different ionization source which on the other h...

Frank Gunzer; Andreas Ulrich…

2010-03-01T23:59:59.000Z

171

Electron cloud instabilities in the Proton Storage Ring and Spallation Neutron Source  

Science Journals Connector (OSTI)

Electron cloud instabilities in the Los Alamos Proton Storage Ring and those foreseen for the Oak Ridge Spallation Neutron Source are examined theoretically, numerically, and experimentally.

M. Blaskiewicz; M. A. Furman; M. Pivi; R. J. Macek

2003-01-21T23:59:59.000Z

172

Electron Acceleration Experiments by Using a Density-tapered Capillary Plasma Source  

Science Journals Connector (OSTI)

We have developed a density-tapered capillary plasma source for high energy electron generation by using the laser wakefield acceleration, where the dephasing problem will be...

Suk, Hyyong; Nam, Inhyuk; Kim, Minseok; Lee, Seungwoo; Lee, Taehee

173

RF-driven ion source with a back-streaming electron dump  

SciTech Connect (OSTI)

A novel ion source is described having an improved lifetime. The ion source, in one embodiment, is a proton source, including an external RF antenna mounted to an RF window. To prevent backstreaming electrons formed in the beam column from striking the RF window, a back streaming electron dump is provided, which in one embodiment is formed of a cylindrical tube, open at one end to the ion source chamber and capped at its other end by a metal plug. The plug, maintained at the same electrical potential as the source, captures these backstreaming electrons, and thus prevents localized heating of the window, which due to said heating, might otherwise cause window damage.

Kwan, Joe; Ji, Qing

2014-05-20T23:59:59.000Z

174

A Plasma-Cathode Electron Source for Focused-Beam Generation in the Fore-Pump Pressure Range  

Science Journals Connector (OSTI)

A plasma electron source is described that forms a focused beam ... is generated in a hollow-cathode discharge. Electrons are extracted through a single emission hole in the anode. The source provides an electron

V. A. Burdovitsin; I. S. Zhirkov; E. M. Oks…

175

Expansion of nanoplasmas and laser-driven nuclear fusion in single exploding clusters  

SciTech Connect (OSTI)

The expansion of laser-irradiated clusters can be controlled by acting on the amount of energy delivered to the electrons. When increasing the electron energy, the expansion regime varies smoothly from a quasineutral, hydrodinamic-like to a Coulomb explosion (CE), as revealed by self-consistent kinetic analysis. A double-pump irradiation scheme can produce hybrid expansion regimes wherein a slow hydrodynamic expansion is followed by a fast CE, leading to ion overtaking and producing multiple ion flows expanding with different velocities, which can lead to intracluster fusion reactions in homonuclear deuterium clusters.

Peano, F.; Martins, J. L.; Silva, L. O. [GoLP/Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Fonseca, R. A. [GoLP/Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Departamento de Ciencias e Tecnologias da Informacao, Instituto Superior de Ciencias do Trabalho e da Empresa, 1649-026 Lisboa (Portugal); Peinetti, F.; Mulas, R.; Coppa, G. [Dipartimento di Energetica, Politecnico di Torino, 10129 Torino (Italy)

2008-09-07T23:59:59.000Z

176

Synthesis of AuPd alloyed nanoparticles via room-temperature electron reduction with argon glow discharge as electron source  

Science Journals Connector (OSTI)

Argon glow discharge has been employed as a cheap, environmentally friendly, and convenient electron source for simultaneous reduction of HAuCl4 and PdCl2...on the anodic aluminum oxide (AAO) substrate. The therm...

Manman Yang; Zongyuan Wang; Wei Wang; Chang-jun Liu

2014-08-01T23:59:59.000Z

177

A 10 GHz electron-cyclotron-resonance (ECR) ion source for ion-electron and ion-atom collision studies  

Science Journals Connector (OSTI)

In order to extend our investigations in the field of electronion collision studies involving ions in high charge states, we decided to build a newly designed 10 GHz Electron-Cyclotron-Resonance Ion Source. The n...

M. Liehr; M. Schlapp; E. Salzborn

1991-01-01T23:59:59.000Z

178

Development of High-Gradient Dielectric Laser-Driven Particle Accelerator Structures  

SciTech Connect (OSTI)

The thrust of Stanford's program is to conduct research on high-gradient dielectric accelerator structures driven with high repetition-rate, tabletop infrared lasers. The close collaboration between Stanford and SLAC (Stanford Linear Accelerator Center) is critical to the success of this project, because it provides a unique environment where prototype dielectric accelerator structures can be rapidly fabricated and tested with a relativistic electron beam.

Byer, Robert L.

2013-11-07T23:59:59.000Z

179

PROGRESS AND FUTURE DIRECTIONS IN BRIGHTNESS ELECTRON BEAM SOURCES...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

structure of the particles (e - e + , e - p colliders). The quality of X-rays production improved dramatically only after the electron accelerators were introduced. The...

180

Electron-beam-driven nanoscale metamaterial light sources  

Science Journals Connector (OSTI)

We show experimentally that beams of free electrons can induce light emission from nanoscale planar photonic metamaterials. Wavelengths of emitted light are determined by both the...

Adamo, Giorgio; Ou, Jun-Yu; MacDonald, Kevin; De Angelis, Francesco; Di Fabrizio, Enzo; Zheludev, Nikolay

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Fast ignition of inertial fusion targets by laser-driven carbon beams  

E-Print Network [OSTI]

Two-dimensional simulations of ion beam driven fast ignition are presented. Ignition energies of protons with Maxwellian spectrum and carbon ions with quasi-monoenergetic and Maxwellian energy distributions are evaluated. The effect of the coronal plasma surrounding the compressed Deuterium-Tritium is studied for three different fuel density distributions. It is found that quasi- monoenergetic ions have better coupling with the compressed Deuterium-Tritium and substantially lower ignition energies. Comparison of quasi-monoenergetic carbon ions and relativistic electrons as ignitor beams shows similar laser energy requirements, provided that a laser to quasi-monoenergetic carbon ion conversion efficiency around 10% can be achieved.

Honrubia, J J; Temporal, M; Hegelich, B M; Meyer-ter-Vehn, J

2009-01-01T23:59:59.000Z

182

Laser-driven deflection arrangements and methods involving charged particle beams  

DOE Patents [OSTI]

Systems, methods, devices and apparatus are implemented for producing controllable charged particle beams. In one implementation, an apparatus provides a deflection force to a charged particle beam. A source produces an electromagnetic wave. A structure, that is substantially transparent to the electromagnetic wave, includes a physical structure having a repeating pattern with a period L and a tilted angle .alpha., relative to a direction of travel of the charged particle beam, the pattern affects the force of the electromagnetic wave upon the charged particle beam. A direction device introduces the electromagnetic wave to the structure to provide a phase-synchronous deflection force to the charged particle beam.

Plettner, Tomas (San Ramon, CA); Byer, Robert L. (Stanford, CA)

2011-08-09T23:59:59.000Z

183

Laser-driven formation of a high-pressure phase in amorphous silica  

SciTech Connect (OSTI)

A combination of electron diffraction and infrared reflectance measurements shows that synthetic silica transforms partially into stishovite under high-intensity (GW/cm2) laser irradiation, probably by the formation of a dense ionized plasma above the silica surface. During the transformation the silicon coordination changes from four-fold to six-fold and the silicon-oxygen bond changes from mostly covalent to mostly ionic, such that optical properties of the transformed material differ significantly from those of the original glass. This phase transformation offers one suitable mechanism by which laser-induced damage grows catastrophically once initiated, thereby dramatically shortening the service lifetime of optics used for high-power photonics applications such as inertial confinement fusion.

Salleo, Alberto; Taylor, Seth T.; Martin, Michael C.; Panero, Wendy R.; Jeanloz, Raymond; Genin, Francois Y.; Sands, Timothy

2002-05-31T23:59:59.000Z

184

Front-End Electron Transfer Dissociation: A New Ionization Source  

Science Journals Connector (OSTI)

Electron transfer dissociation (ETD), a technique that provides efficient fragmentation while depositing little energy into vibrational modes, has been widely integrated into proteomics workflows. Current implementations of this technique, as well as ...

Lee Earley; Lissa C. Anderson; Dina L. Bai; Christopher Mullen; John E. P. Syka; A. Michelle English; Jean-Jacques Dunyach; George C. Stafford, Jr.; Jeffrey Shabanowitz; Donald F. Hunt; Philip D. Compton

2013-08-02T23:59:59.000Z

185

Apparatus and method for compensating for electron beam emittance in synchronizing light sources  

DOE Patents [OSTI]

A focused optical beam is used to change the path length of the core electrons in electron light sources thereby boosting their efficiency of conversion of electron beam energy to light. Both coherent light in the free electron laser and incoherent light in the synchrotron is boosted by this technique. By changing the path length of the core electrons by the proper amount, the core electrons are caused to stay in phase with the electrons in the outer distribution of the electron beam. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron. 4 figs.

Neil, G.R.

1996-07-30T23:59:59.000Z

186

ECRIS: The electron cyclotron resonance ion sources — (status)  

Science Journals Connector (OSTI)

Ion beam characteristics are often decisive factors for experimental atomic physics and ECR sources for highly charged ions play then an important role [1]. Therefore we recall their basic principles and possi...

R. Geller

1991-01-01T23:59:59.000Z

187

Approach towards integrated simulation for laser-driven fast ignition studies  

E-Print Network [OSTI]

An integrated simulation approach fully based upon particle-in-cell (PIC) model is proposed, which involves both fast particle generation via laser solid-density plasma interaction and transport and energy deposition of the particles in extremely high density plasma. It is realized by introducing two independent systems in a simulation, where the fast particle generation is simulated by a full PIC system and the transport and energy deposition computed by a second PIC system with a reduced field solver. Data of the fast particles generated in the full PIC system are copied to the reduced PIC system in real time as the fast particle source. Unlike a two-region approach, which takes a single PIC system and two field solvers in two plasma density regions, respectively, the present one need not match the field-solvers since the reduced field solver and the full solver adopted respectively in the two systems are independent. A simulation case is presented, which demonstrates that this approach can be applied to in...

Wang, W -M; Sheng, Z -M; Li, Y -T

2014-01-01T23:59:59.000Z

188

Investigation of an electron string ion source with field emission cathode  

SciTech Connect (OSTI)

The string mode of operation for an electron beam ion source uses axially oscillating electrons in order to reduce power consumption, also simplifying the construction by omitting the collector with cooling requirements and has been called electron string ion source (ESIS). We have started a project (supported by INTAS and GSI) to use Schottky field emitting cathode tips for generating the electron string. The emission from these specially conditioned tips is higher by orders of magnitude than the focused Brillouin current density at magnetic fields of some Tesla and electron energies of some keV. This may avoid the observed instabilities in the transition from axially oscillating electrons to the string state of the electron plasma, opening a much wider field of possible operating parameters for an ESIS. Besides the presentation of the basic features, we emphasize in this paper a method to avoid damaging of the field emission tip by backstreaming ions.

Becker, R.; Currell, F. J.; Donets, E. D.; Donets, E. E.; Kester, O.; Quint, W.; Ptitsin, V. E. [IAP, Universitaet Frankfurt, Max von Laue-Strasse 1, D-60438 Frankfurt (Germany); QUB, Belfast BT7 1NN (United Kingdom); Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); GSI, Planckstrasse 1, D-64291 Darmstadt (Germany); Institute for Analytical Instrumentation of the Russian Academy of Sciences, Rizhsky Prospect 26, 190103 St. Petersburg (Russian Federation)

2008-02-15T23:59:59.000Z

189

Single Atom Electron and Ion Sources and Their Applications  

E-Print Network [OSTI]

- energy electron point projection microscope, PPM) (37, 38) 1. (shadow microscopy) (shadow image-walled carbon nanotubes, SWNTs) (111) (pizeo-scanner) X- Y-Z (scanning tunneling microscope) 3. (a on the screen (mm) Intensity(Arb.Units) (c) (a) (b) Q FWHM P (a) (b)Dd sample holder detector-MCP #12;13 98

190

An electron source with a multiarc plasma emitter for obtaining submillisecond pulsed megawatt beams  

Science Journals Connector (OSTI)

An electron source with a plasma emitter based on an...2...area. The arc-current amplitude for each cathode amounts to 100–300 A. Under the action of a constant accelerating voltage applied between the plasma emi...

M. S. Vorob’ev; S. A. Gamermaister; V. N. Devyatkov…

2014-06-01T23:59:59.000Z

191

Negative Ion Electron Photodetachment from a Near-Blackbody Photon Source  

Science Journals Connector (OSTI)

Negative Ion Electron Photodetachment from a Near-Blackbody Photon Source ... 12-15 For most negative ions, the ambient flux of photons from other sources, including the cell walls and the filament used in ion generation, is too small to be significant. ... When the filament voltage is pulsed negative, electrons from the heated filament are temporarily accelerated toward the adjacent trapping plate and into the cell, producing negative ions via dissociative attachment with neutral molecules. ...

Gordon A. Janaway; John I. Brauman

2000-01-21T23:59:59.000Z

192

Hybrid single-electron transistor as a source of quantized electric current  

E-Print Network [OSTI]

LETTERS Hybrid single-electron transistor as a source of quantized electric current JUKKA P. PEKOLA of a hybrid normal-metal­ superconductor turnstile in the form of a one-island single- electron transistor currents in the nano-ampere range but their accuracy is still limited. Surprisingly, a simple hybrid single

Loss, Daniel

193

Further observations on the operation of a GaAs polarized electron source  

SciTech Connect (OSTI)

We report on several important features of GaAs polarized electron source operation. Specifically we point out the beneficial effect on crystal lifetime produced by the constant low-level application of cesium from a dispenser embedded in an extraction anode. Using our experience in low-energy polarized electron-atom scattering as a reference, we also discuss the importance of frequent energy calibrations of GaAs electron beams for high-resolution investigations.

Guo, X.Q.; Crowe, D.M.; Lubell, M.S.; Tang, F.C.; Vasilakis, A. (Department of Physics, The City College of CUNY, New York, New York 10031 (USA)); Eminyan, M. (Laboratoire de Physique Atomique, Tour 24, Universite Paris VII, F-75251 Paris (France)); Slevin, J. (Department of Experimental Physics, St. Patrick's College, Maynooth, County Kildare (Ireland))

1990-07-01T23:59:59.000Z

194

Laser-Driven Growth of Silver Nanoplates on p-Type GaAs Substrates and Their Surface-Enhanced Raman Scattering Activity  

Science Journals Connector (OSTI)

Laser-Driven Growth of Silver Nanoplates on p-Type GaAs Substrates and Their Surface-Enhanced Raman Scattering Activity ... Each wafer was cut into ?1 cm × 1 cm square pieces along their cleavage planes (i.e., [01?1?] and [01?1]) and were cleaned by immersing them in a 2% hydrofluoric acid (HF) aqueous solution (Fisher) for 5 min. ... Continued growth smoothes the stepped edges of the oligomers and fuses them into thicker nanoplates whose thicknesses are approximately equal to the sum of the individual plate thicknesses before fusion (Figure 5c). ...

Yugang Sun; Matthew Pelton

2009-03-20T23:59:59.000Z

195

Source-wave angular-momentum effects on electron-diffraction patterns  

Science Journals Connector (OSTI)

We use a simple model to predict when electron-emission diffraction patterns from surfaces will have peaks or dips along internuclear axes. A high angular-momentum electron wave emitted from an atom acts like an s wave (l=0) in an extra centrifugal potential. This extra potential changes the electron’s effective wave number and phase shift, altering the conditions for constructive interference when this wave scatters from nearby atoms. We demonstrate that the difference in source-wave angular momentum between Cu M2,3M4,5M4,5 Auger and Cu 3p photoelectrons explains the difference between their emission angular distributions from surfaces: the Auger-electron emission has a predominantly f-like source wave (l=3) and destructive interference in the forward electron-scattering direction (‘‘silhouette’’) while the photoelectron has lower angular momentum and constructive interference (‘‘peak’’). As long as this effect is considered, Auger-electron emission patterns can be used to determine surface structures. The unusual Auger-electron emission patterns observed by Frank et al. [Science 247, 182 (1990)] can be explained as due to high source-wave angular momentum and low electron energy.

John J. Barton and Louis J. Terminello

1992-11-15T23:59:59.000Z

196

Production of large resonant plasma volumes in microwave electron cyclotron resonance ion sources  

DOE Patents [OSTI]

Microwave injection methods are disclosed for enhancing the performance of existing electron cyclotron resonance (ECR) ion sources. The methods are based on the use of high-power diverse frequency microwaves, including variable-frequency, multiple-discrete-frequency, and broadband microwaves. The methods effect large resonant ``volume`` ECR regions in the ion sources. The creation of these large ECR plasma volumes permits coupling of more microwave power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present ECR ion sources. 5 figs.

Alton, G.D.

1998-11-24T23:59:59.000Z

197

Grating monochromator for electron cyclotron resonance ion source operation  

SciTech Connect (OSTI)

Recently, we started to observe optical line spectra from an ECR plasma using a grating monochromator with a photomultiplier. The light intensity of line spectrum from the ECR plasma had a strong correlation with ion beam intensity measured by a magnetic mass analyzer. This correlation is a significant information for beam tuning because it allows the extraction of the desired ion species from the ECR plasma. Separation of ion species of the same charge to mass ratio with an electromagnetic mass analyzer is known to be an exceptionally complex process, but this research gives new insights into its simplification. In this paper, the grating monochromator method for beam tuning of a Hyper-ECR ion source as an injector for RIKEN azimuthal varying field (AVF) cyclotron is described.

Muto, Hideshi [Center of General Education, Tokyo University of Science, Suwa, 5000-1 Toyohira, Chino Nagano 391-0292 (Japan)] [Center of General Education, Tokyo University of Science, Suwa, 5000-1 Toyohira, Chino Nagano 391-0292 (Japan); Ohshiro, Yukimitsu; Yamaka, Shouichi; Watanabe, Shin-ichi; Yamaguchi, Hidetoshi; Shimoura, Susumu [Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Riken Campus, Wako Saitama 351-0198 (Japan)] [Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Riken Campus, Wako Saitama 351-0198 (Japan); Oyaizu, Michihiro; Kase, Masayuki [RIKEN Nishina Center for Accelerator-Based Science, Wako Saitama 351-0198 (Japan)] [RIKEN Nishina Center for Accelerator-Based Science, Wako Saitama 351-0198 (Japan); Kubono, Shigeru [Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Riken Campus, Wako Saitama 351-0198 (Japan) [Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Riken Campus, Wako Saitama 351-0198 (Japan); RIKEN Nishina Center for Accelerator-Based Science, Wako Saitama 351-0198 (Japan); Institute of Modern Physics, Chinese Academy of Sciences, Nanchang Road 509, Lanzhou 730000 (China); Hattori, Toshiyuki [Heavy Ion Cancer Therapy Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage Chiba 263-855 (Japan)] [Heavy Ion Cancer Therapy Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage Chiba 263-855 (Japan)

2013-07-15T23:59:59.000Z

198

Initial source of microbunching instability studies in a free electron laser injector  

SciTech Connect (OSTI)

We present the first experimental studies of the initial source of electron beam microbunching instability in a free electron laser (FEL) injector. By utilizing for the studies a transform-limited laser pulse at the photocathode, we eliminated laser-induced microbunching at the National Synchrotron Light Source Source Development Laboratory (SDL). The detailed measurements of the resulting electron beam led us to conclude that, at SDL, microbunching arising from shot noise is not amplified to any significant level, thereby allowing us to set an upper limit on the initial modulation depth of microbunching arising from shot noise. Our analysis demonstrated that the only significant source of microbunching instability under normal operational conditions at SDL is the longitudinal modulation of the photocathode laser pulse. Our work shows that assuring a longitudinally smoothed photocathode laser pulse allows mitigating microbunching instability at a typical FEL injector with a moderate microbunching gain.

Seletskiy, S.; Hidaka, Y; Murphy, J.B.; Podobedov, B.; Qian, H.; Shen, Y.; Wang, X.J.; Yang, X

2011-11-16T23:59:59.000Z

199

Effective temperature of an ultracold electron source based on near-threshold photoionization  

Science Journals Connector (OSTI)

Abstract We present a detailed description of measurements of the effective temperature of a pulsed electron source, based on near-threshold photoionization of laser-cooled atoms. The temperature is determined by electron beam waist scans, source size measurements with ion beams, and analysis with an accurate beam line model. Experimental data is presented for the source temperature as a function of the wavelength of the photoionization laser, for both nanosecond and femtosecond ionization pulses. For the nanosecond laser, temperatures as low as 14±3 K were found; for femtosecond photoionization, 30±5 K is possible. With a typical source size of 25 ? m , this results in electron bunches with a relative transverse coherence length in the 10?4 range and an emittance of a few nm rad.

W.J. Engelen; E.P. Smakman; D.J. Bakker; O.J. Luiten; E.J.D. Vredenbregt

2014-01-01T23:59:59.000Z

200

Development of a high average current polarized electron source with long cathode operational lifetime  

Science Journals Connector (OSTI)

Substantially more than half of the electromagnetic nuclear physics experiments conducted at the Continuous Electron Beam Accelerator Facility of the Thomas Jefferson National Accelerator Facility (Jefferson Laboratory) require highly polarized electron beams, often at high average current. Spin-polarized electrons are produced by photoemission from various GaAs-based semiconductor photocathodes, using circularly polarized laser light with photon energy slightly larger than the semiconductor band gap. The photocathodes are prepared by activation of the clean semiconductor surface to negative electron affinity using cesium and oxidation. Historically, in many laboratories worldwide, these photocathodes have had short operational lifetimes at high average current, and have often deteriorated fairly quickly in ultrahigh vacuum even without electron beam delivery. At Jefferson Lab, we have developed a polarized electron source in which the photocathodes degrade exceptionally slowly without electron emission, and in which ion back bombardment is the predominant mechanism limiting the operational lifetime of the cathodes during electron emission. We have reproducibly obtained cathode 1/e dark lifetimes over two years, and 1/e charge density and charge lifetimes during electron beam delivery of over 2×105???C/cm2 and 200 C, respectively. This source is able to support uninterrupted high average current polarized beam delivery to three experimental halls simultaneously for many months at a time. Many of the techniques we report here are directly applicable to the development of GaAs photoemission electron guns to deliver high average current, high brightness unpolarized beams.

C. K. Sinclair; P. A. Adderley; B. M. Dunham; J. C. Hansknecht; P. Hartmann; M. Poelker; J. S. Price; P. M. Rutt; W. J. Schneider; M. Steigerwald

2007-02-07T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Neutralization of an ion beam from the end-Hall ion source by a plasma electron source based on a discharge in crossed E × H fields  

Science Journals Connector (OSTI)

The possibility of using a plasma electron source (PES) with a discharge in crossed E × H...field for compensating the ion beam from an end-Hall ion source (EHIS) is analyzed. The PES used ... and acceleration re...

A. P. Dostanko; D. A. Golosov

2009-10-01T23:59:59.000Z

202

Single-electron source: Adiabatic versus nonadiabatic emission  

Science Journals Connector (OSTI)

We investigate adiabatic and nonadiabatic emission of single particles into an edge state using an analytically solvable dynamical scattering matrix model of an on-demand source. We compare adiabatic and nonadiabatic emissions by considering two geometries: a collider geometry where two emitters are coupled to two different edge states and a series geometry where two emitters are coupled to the same edge state. Most effects observed for adiabatic emitters also occur for nonadiabatic emitters. In particular this applies to effects arising due to the overlap of wave packets colliding at a quantum point contact. Specifically we compare the Pauli peak (the fermionic analog of the bosonic Hong-Ou-Mandel dip) for the adiabatic and nonadiabatic collider and find them to be similar. In contrast we find a striking difference between the two operating conditions in the series geometry in which particles are emitted into the same edge state. Whereas the squared average charge current can be nullified for both operating conditions, the heat current can be made to vanish only with adiabatic emitters.

Michael Moskalets; Géraldine Haack; Markus Büttiker

2013-03-29T23:59:59.000Z

203

Effect of Electron Source to Energy Resolution in Electron Velocity Analysis — Interpretation of Boersch Effect  

Science Journals Connector (OSTI)

In 1954, Boersch [1] reported that a width of the emission spectrum of an electron beam increases with the beam current or the current density. Those experiments were carried out by a retarding potential analyzer...

T. Ichinokawa

1969-01-01T23:59:59.000Z

204

Simulation and optimization of a 10 A electron gun with electrostatic compression for the electron beam ion source  

SciTech Connect (OSTI)

Increasing the current density of the electron beam in the ion trap of the Electron Beam Ion Source (EBIS) in BNL's Relativistic Heavy Ion Collider facility would confer several essential benefits. They include increasing the ions' charge states, and therefore, the ions' energy out of the Booster for NASA applications, reducing the influx of residual ions in the ion trap, lowering the average power load on the electron collector, and possibly also reducing the emittance of the extracted ion beam. Here, we discuss our findings from a computer simulation of an electron gun with electrostatic compression for electron current up to 10 A that can deliver a high-current-density electron beam for EBIS. The magnetic field in the cathode-anode gap is formed with a magnetic shield surrounding the gun electrodes and the residual magnetic field on the cathode is (5 Division-Sign 6) Gs. It was demonstrated that for optimized gun geometry within the electron beam current range of (0.5 Division-Sign 10) A the amplitude of radial beam oscillations can be maintained close to 4% of the beam radius by adjusting the injection magnetic field generated by a separate magnetic coil. Simulating the performance of the gun by varying geometrical parameters indicated that the original gun model is close to optimum and the requirements to the precision of positioning the gun elements can be easily met with conventional technology.

Pikin, A.; Beebe, E. N.; Raparia, D. [Brookhaven National Laboratory, Upton, New York 11973 (United States)

2013-03-15T23:59:59.000Z

205

Neutron source in the MCNPX shielding calculating for electron accelerator driven facility  

SciTech Connect (OSTI)

Argonne National Laboratory (ANL) of USA and Kharkov Inst. of Physics and Technology (KIPT) of Ukraine have been collaborating on the design development of an experimental neutron source facility. It is an accelerator driven system (ADS) utilizing a subcritical assembly driven by electron accelerator. The facility will be utilized for performing basic and applied nuclear researches, producing medical isotopes, and training young nuclear specialists. Monte Carlo code MCNPX has been utilized as a design tool due to its capability to transport electrons, photons, and neutrons at high energies. However the facility shielding calculations with MCNPX need enormous computational resources and the small neutron yield per electron makes sampling difficulty for the Monte Carlo calculations. A method, based on generating and utilizing neutron source file, was proposed and tested. This method reduces significantly the required computer resources and improves the statistics of the calculated neutron dose outside the shield boundary. However the statistical errors introduced by generating the neutron source were not directly represented in the results, questioning the validity of this methodology, because an insufficiently sampled neutron source can cause error on the calculated neutron dose. This paper presents a procedure for the validation of the generated neutron source file. The impact of neutron source statistic on the neutron dose is examined by calculating the neutron dose as a function of the number of electron particles used for generating the neutron source files. When the value of the calculated neutron dose converges, it means the neutron source has scored sufficient records and statistic does not have apparent impact on the calculated neutron dose. In this way, the validity of neutron source and the shield analyses could be verified. (authors)

Zhong, Z.; Gohar, Y. [Nuclear Engineering Div., Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

2012-07-01T23:59:59.000Z

206

Model simulations of continuous ion injection into electron-beam ion source trap with slanted electrostatic mirrora...  

E-Print Network [OSTI]

Model simulations of continuous ion injection into electron-beam ion source trap with slanted developed by this group on DIONE electron-beam ion source EBIS .2­4 The most popular method of injecting 2 December 2007; published online 19 February 2008 The efficiency of trapping ions in an electron

207

BNL test electron beam ion source operation on a 100 kV platform ,,abstract...a...,b...  

E-Print Network [OSTI]

BNL test electron beam ion source operation on a 100 kV platform ,,abstract...a...,b... E. N. Beebe to build an electron beam ion source EBIS that will satisfy the requirements of the relativistic heavy ion program. Development studies continue to be carried out on the BNL test EBIS, a half-length full electron

208

A low emittance, flat-beam electron source for linear colliders  

Science Journals Connector (OSTI)

We present a method to generate a flat (large horizontal to vertical emittance ratio) electron beam suitable for linear colliders. The concept is based on a round-beam rf photoinjector with finite solenoid field at the cathode together with a special beam optics adapter. Computer simulations of this new type of beam source show that the beam quality required for a linear collider may be obtainable without the need for an electron damping ring.

R. Brinkmann; Y. Derbenev; K. Flöttmann

2001-05-18T23:59:59.000Z

209

Electron Source in Photoinduced Hydrogen Production on Pt-supported TiO2 Particles  

Science Journals Connector (OSTI)

Electron Source in Photoinduced Hydrogen Production on Pt-supported TiO2 Particles ... After recovering the TiO2/Pt particles used in the long-term reaction, they were reused in a photocatalytic H+ reduction by adding methanol as an electron donor, but no H2 production was observed showing that the TiO2/Pt particles have lost their photocatalytic activity after the long-term reaction. ... A 100 W high-pressure Hg lamp was used as a light source. ...

Toshiyuki Abe; Eiji Suzuki; Kentaro Nagoshi; Kohichi Miyashita; Masao Kaneko

1999-02-04T23:59:59.000Z

210

Note: Production of a mercury beam with an electron cyclotron resonance ion source  

SciTech Connect (OSTI)

An electron cyclotron resonance ion source has been utilized to produce mercury beams with intensities of 4.5 e?A of {sup 202}Hg{sup 29+} and 3.0 e?A of {sup 202}Hg{sup 31+} from natural abundance mercury metal. The production technique relies on the evaporation of liquid mercury into the source plasma vacuum region and utilizes elemental mercury instead of a volatile organic compound as the neutral feed material.

Vondrasek, R.; Pardo, R.; Scott, R. [Physics Division, Argonne National Laboratory, Lemont, Illinois 60439 (United States)] [Physics Division, Argonne National Laboratory, Lemont, Illinois 60439 (United States)

2013-11-15T23:59:59.000Z

211

Low-energy, high-current, ion source with cold electron emitter  

SciTech Connect (OSTI)

An ion source based on a two-stage discharge with electron injection from a cold emitter is presented. The first stage is the emitter itself, and the second stage provides acceleration of injected electrons for gas ionization and formation of ion flow (<20 eV, 5 A dc). The ion accelerating system is gridless; acceleration is accomplished by an electric field in the discharge plasma within an axially symmetric, diverging, magnetic field. The hollow cathode electron emitter utilizes an arc discharge with cathode spots hidden inside the cathode cavity. Selection of the appropriate emitter material provides a very low erosion rate and long lifetime.

Vizir, A. V.; Oks, E. M. [High Current Electronics Institute, Russian Academy of Sciences, Tomsk 634055 (Russian Federation); State University of Control Systems and Radioelectronics, Tomsk 634050 (Russian Federation); Shandrikov, M. V.; Yushkov, G. Yu. [High Current Electronics Institute, Russian Academy of Sciences, Tomsk 634055 (Russian Federation)

2012-02-15T23:59:59.000Z

212

Accuracy of the quantum capacitor as a single-electron source  

Science Journals Connector (OSTI)

A periodically driven quantum capacitor may function as an on-demand single-electron source as it has recently been demonstrated experimentally. However, the accuracy at which single electrons are emitted is not yet understood. Here we consider a conceptually simple model of a quantum capacitor and find analytically the noise spectrum as well as the counting statistics of emitted electrons. We find that the failure rate of the capacitor can be arbitrarily small when operated under favorable conditions. Our theoretical predictions may be tested in future experiments.

Mathias Albert; Christian Flindt; Markus Büttiker

2010-07-16T23:59:59.000Z

213

Electron cloud development in the Proton Storage Ring and in the Spallation Neutron Source  

Science Journals Connector (OSTI)

We have applied our simulation code POSINST to evaluate the contribution to the growth rate of the electron cloud instability in proton storage rings. In particular, we present here recent simulation results for the main features of the electron cloud in the storage ring of the Spallation Neutron Source at Oak Ridge, and updated results for the Proton Storage Ring at Los Alamos. A key ingredient in our model is a detailed description of the secondary electron emission process, including a refined model for the emitted energy spectrum, and for the three main components of the secondary yield, namely, the true secondary, rediffused and backscattered components.

M. T. F. Pivi and M. A. Furman

2003-03-05T23:59:59.000Z

214

Production of energetic neutral particles and low energy electrons from four anode rods ion source  

SciTech Connect (OSTI)

The factors affecting the energetic neutral current, the low energy electron current, and the positive ion current emerging from a four-anode-rods ion source have been studied using argon gas. The neutral and electron current were measured using a simple, new technique. It was found that the energetic neutral current and the electron current depend on the positive ion current and the gas pressure. The ratio of the neutral and electron current to the positive ion current increases by increasing the gas pressure. Also it was found that at a pressure equal to 9 × 10{sup ?4} mmHg, the ratio of the neutral to the positive ion current reaches 2.34 while the ratio of the electron current to the positive ion current reaches 1.7.

Mostafa, O. A.; El-Khabeary, H.; Abdel Reheem, A. M. [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy Authority P.N.13759, Inchas, Cairo (Egypt)] [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy Authority P.N.13759, Inchas, Cairo (Egypt)

2013-11-15T23:59:59.000Z

215

Nano electron source fabricated by beam-induced deposition and its unique feature  

Science Journals Connector (OSTI)

Abstract The fabrication of nanoscale field emitters with gate structures using beam-induced deposition and their field emission properties are described. Nano electron sources can be fabricated by electron-beam-induced deposition without additional processes. The inherent issues of process contamination and the effectiveness of post cleaning using annealing or radical oxygen gas exposure to remove contaminants introduced during beam deposition are also discussed. In addition, coherent electron beams for electron wave interference emitted from a beam-deposited Pt field emitter were investigated by field emission microscopy and field ion microscopy. The interference fringe patterns observed for beam-deposited Pt field emitters were attributed to electron wave interference occurring at two adjacent emission sites on a single Pt nanocrystal.

Katsuhisa Murakami; Mikio Takai

2015-01-01T23:59:59.000Z

216

Electron heat transport in the magnetic filter of a volume plasma-based source of H?/D? ions  

Science Journals Connector (OSTI)

A time-independent one-dimensional model of the electron energy balance in the region of the ... magnetic filter of a volume plasma-based ion source is justified. The local electron energy balance equation and th...

O. L. Veresov; S. V. Grigorenko; S. Yu. Udovichenko

2000-08-01T23:59:59.000Z

217

Field-Emission Properties in the ERL-Electron Source Vaibhav Kukreja  

E-Print Network [OSTI]

Field-Emission Properties in the ERL-Electron Source Vaibhav Kukreja Department of Physics, Cornell field emission poses many risks to the function and the structure of the gun. We have tested five electrodes with different composition and surface treatment. In this paper, we will discuss their emission

Hoffstaetter, Georg

218

Source: "Careers for Electrical Engineers and Computer Scientists" Institute of Electrical and Electronics Engineers HISTORICAL OVERVIEW  

E-Print Network [OSTI]

Source: "Careers for Electrical Engineers and Computer Scientists" © Institute of Electrical and Electronics Engineers HISTORICAL OVERVIEW PREPARED BY THE IEEE HISTORY CENTER RUTGERS UNIVERSITY ELECTRICITY IN THE 1880s The organization of the electrical engineering profession in America in the1880s

New Hampshire, University of

219

Calculated spin polarization of field-assisted GaAs electron source  

Science Journals Connector (OSTI)

Calculations are reported showing that for the field-assisted GaAs NEA photocathode, the spin polarization of emitted electrons can be 3.6 times higher than for non-field GaAs sources. The reason for this is that...

B. Yang; V. Guidi; L. Tecchio

1993-02-01T23:59:59.000Z

220

The Most Likely Sources of High Energy Cosmic-Ray Electrons in Supernova Remnants  

E-Print Network [OSTI]

Evidences of non-thermal X-ray emission and TeV gamma-rays from the supernova remnants (SNRs) has strengthened the hypothesis that primary Galactic cosmic-ray electrons are accelerated in SNRs. High energy electrons lose energy via synchrotron and inverse Compton processes during propagation in the Galaxy. Due to these radiative losses, TeV electrons liberated from SNRs at distances larger than ~1 kpc, or times older than ~10^5 yr, cannot reach the solar system. We investigated the cosmic-ray electron spectrum observed in the solar system using an analytical method, and considered several candidate sources among nearby SNRs which may contribute to the high energy electron flux. Especially, we discuss the effects for the release time from SNRs after the explosion, as well as the deviation of a source spectrum from a simple power-law. From this calculation, we found that some nearby sources such as the Vela, Cygnus Loop, or Monogem could leave unique signatures in the form of identifiable structure in the energ...

Kobayashi, T; Yoshida, K; Nishimura, J

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
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221

The effect of the H{sub 2} density on the electron energy distribution in H{sup ?} ion sources  

SciTech Connect (OSTI)

The electron energy distribution in H{sup ?} ion sources is studied. By three-dimensional Monte Carlo simulations (3D-MCC) and cross sections of collisions, the crucial collisions in the JAEA 10A are chosen to develop theoretical models for the low electron temperature and the high electron temperature, respectively. The effects of the H{sub 2} density on the low electron temperature and the high electron temperature in H{sup ?} ion sources are predicted with analytic expressions and verified by 3D-MCC. The results show that both the low and high electron temperatures become lower while n{sub H2} increases.

Wang, Huihui; Meng, Lin; Liu, Dagang; Liu, Laqun; Yang, Chao [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China)] [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China)

2013-09-15T23:59:59.000Z

222

Electron capture and electron transport by fast ions penetrating solids: An open quantum system approach with sources and sinks  

Science Journals Connector (OSTI)

We present a joint theoretical and experimental study of the time evolution of electronic states of highly charged hydrogenic ions formed by capture during transmission through solids as they undergo multiple collisions and radiative decay. For this transport problem we have developed an inhomogeneous nonunitary Lindblad master equation that allows for a description of open quantum systems with both sinks (electron loss) and source (capture) present. We apply this theoretical framework to study transient coherences created in electron capture by 13.6MeV?amu Ar18+ ions transmitted through amorphous carbon foils and decoherence during subsequent interaction with the foil. In the limit of thin targets we can directly probe electron capture cross sections under single collision conditions, while for thicker targets we follow the partially coherent dynamics of the open quantum system in interaction with the solid as a function of interaction time. The calculated results are in close agreement with experimental data obtained at the LISE facility in GANIL. Photon intensities from excited argon ions were determined through high resolution x-ray spectroscopy in which individual fine structure components were resolved. Measurements were performed for a wide range of carbon foil thickness to study the time development of the excited state populations.

Marek Seliger; Carlos O. Reinhold; Tatsuya Minami; David R. Schultz; Michael S. Pindzola; Shuhei Yoshida; Joachim Burgdörfer; Emily Lamour; Jean-Pierre Rozet; Dominique Vernhet

2007-03-19T23:59:59.000Z

223

Magnet tests and status of the superconducting electron cyclotron resonance source SERSE  

SciTech Connect (OSTI)

At Laboratorio Nazionale del Sud a superconducting 14.5 GHz electron cyclotron resonance (ECR) source will be used as injector for the K-800 superconducting cyclotron. The original project of its magnetic system has been upgraded by taking into account the results of the high B mode operation of the 6.4 GHz SC-ECRIS at MSU-NSCL and now the mirror field may achieve 2.7 T, which is much higher than the confining field of any other ECR source. The magnet design will allow us to operate in a wide range of magnetic configurations making it easy to tune the source. The status of the project will be outlined and the preliminary results of the tests of the superconducting magnets will be described. A brief description of the tests to be carried out on the source during the first period of operation on the test bench in Grenoble follows. {copyright} {ital 1996 American Institute of Physics.}

Ciavola, G.; Gammino, S.; Cafici, M.; Castro, M.; Chines, F.; Marletta, S. [INFN-Laboratorio Nazionale del Sud, Via S. Sofia 44, 95123 Catania (Italy)] [INFN-Laboratorio Nazionale del Sud, Via S. Sofia 44, 95123 Catania (Italy); Alessandria, F. [INFN-LASA, Via F.lli Cervi 201, 20090 Segrate (Midway Islands) (Italy)] [INFN-LASA, Via F.lli Cervi 201, 20090 Segrate (Midway Islands) (Italy); Bourg, F.; Briand, P.; Melin, G.; Lagnier, R.; Seyfert, P. [CEA-Departement de Recherche Fondamentale sur la Matiere Condensee, Centre detudes Nucleaires de Grenoble, 38054 Grenoble Cedex 9 (France)] [CEA-Departement de Recherche Fondamentale sur la Matiere Condensee, Centre detudes Nucleaires de Grenoble, 38054 Grenoble Cedex 9 (France); Gaggero, G.; Losasso, M.; Penco, R. [ANSALDO-GIE, Via N. Lorenzi 8, 16152 Genova (Italy)] [ANSALDO-GIE, Via N. Lorenzi 8, 16152 Genova (Italy)

1996-03-01T23:59:59.000Z

224

Chemical Source Localization Using Electronic Nose Sensors Joy Chiang, Vanessa Tidwell, Patricio S. La Rosa, Arye Nehorai  

E-Print Network [OSTI]

Chemical Source Localization Using Electronic Nose Sensors Joy Chiang, Vanessa Tidwell, Patricio S of this project is to develop a closedloop system to estimate the location of an odor source, using a chemical sensor array mounted on a robotic platform capable of moving in 2D. We model our electronic nose sensors

Nehorai, Arye

225

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 53, NO. 2, APRIL 2006 477 Voltage-Source Active Power Filter Based on  

E-Print Network [OSTI]

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 53, NO. 2, APRIL 2006 477 Voltage-Source Active compensate load current harmonics, keeping better-quality sinusoidal currents from the source. The simulated MODERN power electronics have contributed a great deal to the development of new powerful applications

Catholic University of Chile (Universidad Católica de Chile)

226

Comment on “Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles”  

Science Journals Connector (OSTI)

Comment on “Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles” ... We can suggest at least three more likely (than Ti4+) sources for their mysterious electron donor:? (1) an overlooked inorganic species, (2) Ti3+, and/or (3) organic impurities. ...

Craig L. Perkins; Michael A. Henderson; David E. McCready; Greg S. Herman

2000-12-05T23:59:59.000Z

227

Improvement of efficiency and temperature control of induction heating vapor source on electron cyclotron resonance ion source  

SciTech Connect (OSTI)

An electron cyclotron resonance ion source (ECRIS) is used to generate multicharged ions for many kinds of the fields. We have developed an evaporator by using induction heating method that can generate pure vapor from solid state materials in ECRIS. We develop the new matching and protecting circuit by which we can precisely control the temperature of the induction heating evaporator. We can control the temperature within {+-}15 deg. C around 1400 deg. C under the operation pressure about 10{sup -4} Pa. We are able to use this evaporator for experiment of synthesizing process to need pure vapor under enough low pressure, e.g., experiment of generation of endohedral Fe-fullerene at the ECRIS.

Takenaka, T.; Kiriyama, R.; Kurisu, Y.; Nozaki, D.; Yano, K.; Sato, F.; Kato, Y.; Iida, T. [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan); Muramatsu, M.; Kitagawa, A. [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Uchida, T.; Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama 350-8585 (Japan)

2012-02-15T23:59:59.000Z

228

Development of an electron gun for an ERL based light source in Japan  

SciTech Connect (OSTI)

We have developed a prototype DC photoemission electron gun for a future energy recovery linac (ERL) based light source in Japan. The prototype gun is operated at up to 250 kV and is designed to deliver up to 50 mA beam current. A diagnostic beam line for emittance and bunch length measurements has been constructed. We have also designed a new 500 kV DC gun which is capable of producing up to 10 mA electron current with emittance lower than 1 mm-mrad. The high voltage terminal will be isolated by ten ceramics stacked in series. The new gun will satisfy performance required as an injector for the compact ERL, which will be constructed at KEK site as a prototype of the future ERL light source.

Nishimori, N.; Nagai, R.; Iijima, H.; Hajima, R. [Japan Atomic Energy Agency (JAEA), Tokai, Naka, Ibaraki 319-1195 (Japan); Honda, Y.; Muto, T. [High Energy Accelerator Research Organization (KEK), Oho, Tsukuba, Ibaraki 305-0801 (Japan); Kuriki, M. [Hiroshima University, Kagamiyama, Higashihiroshima, Hiroshima 739-8530 (Japan); Yamamoto, M.; Okumi, S.; Nakanishi, T. [Graduate School of Science, Nagoya University, Nagoya 464-8602 (Japan)

2009-08-04T23:59:59.000Z

229

Module No: 410320Electronic Transactions LawModule Title: Co-requisite:Sources of ObligationsPre-requisite  

E-Print Network [OSTI]

Module No: 410320Electronic Transactions LawModule Title: Co-requisite:Sources of Obligations that arise from the utilization of the electronic information systems based on an elucidation of the nature on the various branches of law. Electronic trade (E-commerce)is defined alongside its rules, and an overview

230

An inverted cylindrical sputter magnetron as metal vapor supply for electron cyclotron resonance ion sources  

SciTech Connect (OSTI)

An inverted cylindrical sputter magnetron device has been developed. The magnetron is acting as a metal vapor supply for an electron cyclotron resonance (ECR) ion source. FEM simulation of magnetic flux density was used to ensure that there is no critical interaction between both magnetic fields of magnetron and ECR ion source. Spatially resolved double Langmuir probe and optical emission spectroscopy measurements show an increase in electron density by one order of magnitude from 1 × 10{sup 10} cm{sup ?3} to 1 × 10{sup 11} cm{sup ?3}, when the magnetron plasma is exposed to the magnetic mirror field of the ECR ion source. Electron density enhancement is also indicated by magnetron plasma emission photography with a CCD camera. Furthermore, photographs visualize the formation of a localized loss-cone - area, when the magnetron is operated at magnetic mirror field conditions. The inverted cylindrical magnetron supplies a metal atom load rate of R > 1 × 10{sup 18} atoms/s for aluminum, which meets the demand for the production of a milliampere Al{sup +} ion beam.

Weichsel, T., E-mail: tim.weichsel@fep.fraunhofer.de; Hartung, U.; Kopte, T. [Fraunhofer Institute for Electron Beam and Plasma Technology, 01277 Dresden (Germany)] [Fraunhofer Institute for Electron Beam and Plasma Technology, 01277 Dresden (Germany); Zschornack, G. [Institute of Solid State Physics, Dresden University of Technology, 01062 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Dresden (Germany)] [Institute of Solid State Physics, Dresden University of Technology, 01062 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Dresden (Germany); Kreller, M.; Silze, A. [DREEBIT GmbH, 01900 Grossroehrsdorf (Germany)] [DREEBIT GmbH, 01900 Grossroehrsdorf (Germany)

2014-05-15T23:59:59.000Z

231

Population distributions in Li vapor excited by a photoionization electron source  

Science Journals Connector (OSTI)

A detailed theoretical and experimental investigation is presented of the excited-level population distribution in a Li-Ne vapor under excitation by a photoionization electron source. This source produces a subnanosecond burst of hot (Te?20 eV) electrons with a peak density in excess of 5×1015 cm-3. The electrons are generated as a result of photoionization of Ne atoms by x rays emitted from a plasma produced by a 100-mJ laser pulse of 600 ps duration. Measurements of Li(1s22p)-atom density, and of electron density, have been performed with subnanosecond time resolution under various conditions of excitation. A comprehensive rate-equation model is described and its predictions are seen to be in good agreement with experiment. It is shown that the population distribution in the Li-Ne vapor is strongly influenced by recombination. Under the conditions of these experiments, rates for this process as high as 3×109 s-1 were observed.

R. G. Caro and J. C. Wang

1986-04-01T23:59:59.000Z

232

DEVELOPMENT OF A COMPACT PHOTO-INJECTOR WITH RFFOCUSING LENS FOR SHORT PULSE ELECTRON SOURCE APPLICATION  

SciTech Connect (OSTI)

For development of compact ultrafast electron source system, we are currently designing a short-pulse RF-gun with RF focusing structure by means of a series of comprehensive modeling analysis processes. EM design of a 2.5 cell resonant cavity with input coupler, acceleration dynamics of photo-emitted electron bunch, EM design of RF-lens with input coupler, and phasespace analysis of focused electron bunch are systematically examined with multi-physics simulators. All the features of the 2.856 GHz cavity geometry were precisely engineered for acceleration energies ranging from 100 keV to 500 keV (safety limited) to be powered by our 5 MW S-band klystron. The klystron (Thales TH2163) and modulator system (ScandiNova K1 turnkey system) were successfully installed and tested. Performance tests of the klystron system show peak output power > 5 MW, as per operation specifications. At the quasi-relativistic energies, the electron source is capable of generating 100fC – 1 pC electron bunch with pulse duration close to 30 fs – 1 ps and transverse size of a few hundred microns. PIC simulations have shown that the electron bunch undergoes fast RF acceleration, rapidly reaching the desired energies, which can be controlled by tuning RF injection phase and input driving power. It has been shown that it is possible to also focus/compress the bunch longitudinally using a RF-lens, which would allow us to control the temporal resolution of the system as well. While our primary analysis has been performed on a 2.5 cell design, we are also looking into half-cell (single cavity) design that is expected to provide the same range of beam energy with a simple configuration.

Grabenhofer, Alexander [Northern Illinois University; Eaton, Douglas W. [ScandiNova systems AB, Uppsala, Sweden

2013-09-01T23:59:59.000Z

233

Roadmap for the design of a superconducting electron cyclotron resonance ion source for Spiral2  

SciTech Connect (OSTI)

A review of today achieved A/Q = 3 heavy ions beams is proposed. The daily operation A/Q = 3 ion beam intensities expected at Spiral2 are at the limit or above best record 3rd generation electron cyclotron resonance ion source (ECRIS) intensities. The necessity to build a new fully superconducting to fulfill these requirements is outlined. A discussion on the volume of the future source is proposed and the minimum value of 12 liters is derived. An analysis of the x-ray absorption superconducting ECRIS is presented based on VENUS experimental data and geometry. This study underlines the necessity to include a complete x-ray study at the time of source conception. The specifications foreseen for the new ECRIS are presented, followed with the roadmap for the design.

Thuillier, T.; Angot, J.; Lamy, T. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des martyrs 38026 Grenoble cedex (France); Barue, C.; Canet, C.; Leherissier, P.; Lemagnen, F.; Maunoury, L. [GANIL, BP 55027, 14076 Caen Cedex 5 (France); Peaucelle, C. [Institut de Physique Nucleaire de Lyon, Universite de Lyon, Universite de Lyon 1, CNRS/IN2P3, Villeurbanne (France)

2012-02-15T23:59:59.000Z

234

Proposed Rabi-Kondo Correlated State in a Laser-Driven Semiconductor Quantum Dot B. Sbierski,1,2  

E-Print Network [OSTI]

. Imamoglu1 1 Institute for Quantum Electronics, ETH Zu¨rich, CH-8093 Zu¨rich, Switzerland 2 Dahlem Center Department of Physics, Yale University, 217 Prospect Street, New Haven, Connecticut 06520, USA (Received 28 by weak laser light, the resulting emission spectrum allows for a direct probe of these correlations

von Delft, Jan

235

Operation of the CAPRICE electron cyclotron resonance ion source applying frequency tuning and double frequency heating  

SciTech Connect (OSTI)

The properties of the electromagnetic waves heating the electrons of the ECR ion sources (ECRIS) plasma affect the features of the extracted ion beams such as the emittance, the shape, and the current, in particular for higher charge states. The electron heating methods such as the frequency tuning effect and the double frequency heating are widely used for enhancing the performances of ECRIS or even for the routine operation during the beam production. In order to better investigate these effects the CAPRICE ECRIS has been operated using these techniques. The ion beam properties for highly charged ions have been measured with beam diagnostic tools. The reason of the observed variations of this performance can be related to the different electromagnetic field patterns, which are changing inside the plasma chamber when the frequency is varying.

Maimone, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); Universita degli Studi di Catania, D.M.F.C.I, Viale A. Doria 6, 95125 Catania (Italy); Tinschert, K.; Lang, R.; Maeder, J.; Rossbach, J.; Spaedtke, P. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); Celona, L. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy)

2012-02-15T23:59:59.000Z

236

Design and validation of an accelerator for an ultracold electron source  

Science Journals Connector (OSTI)

We describe here a specially designed accelerator structure and a pulsed power supply that are essential parts of a high brightness cold atoms-based electron source. The accelerator structure allows a magneto-optical atom trap to be operated inside of it, and also transmits subnanosecond electric field pulses. The power supply produces high voltage pulses up to 30 kV, with a rise time of up to 30 ns. The resulting electric field inside the structure is characterized with an electro-optic measurement and with an ion time-of-flight experiment. Simulations predict that 100 fC electron bunches, generated from trapped atoms inside the structure, reach an emittance of 0.04 mm?mrad and a bunch length of 80 ps.

G. Taban; M. P. Reijnders; S. C. Bell; S. B. van der Geer; O. J. Luiten; E. J. D. Vredenbregt

2008-05-07T23:59:59.000Z

237

Green’s function based space-charge field solver for electron source simulations  

Science Journals Connector (OSTI)

We present a theoretical formulation for calculating the electromagnetic space-charge fields within a simplified electron source geometry using time-dependent Green’s function methods. The source geometry is assumed to be comprised of a flat cathode along with a pipe of arbitrary but uniform cross section. Under the assumption that the beam currents are parallel to the pipe axis, we derive exact solutions for the electromagnetic potentials in the Lorentz gauge. In addition, for the special case of a pipe with rectangular cross section, we present the exact solutions of the electromagnetic potentials for arbitrary beam currents. Finally, we show the results of an analytical benchmark study in which the electromagnetic fields that are solved using the Green’s function method are in excellent agreement (<1% error) with the benchmark fields.

Mark Hess; Chong Shik Park; Daniel Bolton

2007-05-17T23:59:59.000Z

238

Status of the Bio-Nano electron cyclotron resonance ion source at Toyo University  

SciTech Connect (OSTI)

In the paper, the material science experiments, carried out recently using the Bio-Nano electron cyclotron resonance ion source (ECRIS) at Toyo University, are reported. We have investigated several methods to synthesize endohedral C{sub 60} using ion-ion and ion-molecule collision reaction in the ECRIS. Because of the simplicity of the configuration, we can install a large choice of additional equipment in the ECRIS. The Bio-Nano ECRIS is suitable not only to test the materials production but also to test technical developments to improve or understand the performance of an ECRIS.

Uchida, T., E-mail: uchida-t@toyo.jp [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan); Minezaki, H.; Ishihara, S. [Graduate School of Engineering, Toyo University, Kawagoe 350-8585 (Japan)] [Graduate School of Engineering, Toyo University, Kawagoe 350-8585 (Japan); Muramatsu, M.; Kitagawa, A.; Drentje, A. G. [National Institute of Radiological Sciences (NIRS), Chiba 263-8555 (Japan)] [National Institute of Radiological Sciences (NIRS), Chiba 263-8555 (Japan); Rácz, R.; Biri, S. [Institute for Nuclear Research (ATOMKI), H-4026 Debrecen (Hungary)] [Institute for Nuclear Research (ATOMKI), H-4026 Debrecen (Hungary); Asaji, T. [Oshima National College of Maritime Technology, Yamaguchi 742-2193 (Japan)] [Oshima National College of Maritime Technology, Yamaguchi 742-2193 (Japan); Kato, Y. [Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan)] [Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan); Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan) [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan); Graduate School of Engineering, Toyo University, Kawagoe 350-8585 (Japan)

2014-02-15T23:59:59.000Z

239

Philips Light Sources & Electronics is Developing an Efficient, Smaller, Cost-Effective Family of LED Drivers  

Broader source: Energy.gov [DOE]

With the help of DOE funding, Philips Light Sources & Electronics is developing a new family of LED drivers that are more efficient and cost-effective as well as smaller in size than currently available drivers. The new drivers are switch-mode power supplies that are similar to today's drivers, but with an improved design. In addition, they have a different topology—boost plus LLC—for wattages of 40W and above, but they retain the commonly used flyback topology at lower wattages.

240

Summary Report of PESP2008 - The Workshop on Polarized Electron Sources and Polarimeters  

SciTech Connect (OSTI)

The Workshop on Polarized Electron Sources and Polarimeters (PESP2008) was hosted by Jefferson Lab October 1-3, 2008, in association with SPIN2008, continuing a tradition since 1983. The workshop was well attended with 84 registrants, 38 oral presentations and 17 posters. The usual topics were covered: DC and RF photoguns, high voltage issues, photocathodes, drive lasers, vacuum and polarimetry. Detailed accounts of each contribution (oral and poster) appear within these Proceedings. This submission summarizes some of the highlights of the workshop.

Poelker, M. [Thomas Jefferson national Accelerator Facility, 12000 Jefferson Ave., Newport News, VA 23606 (United States)

2009-08-04T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Fullerene-rare gas mixed plasmas in an electron cyclotron resonance ion source  

E-Print Network [OSTI]

A synthesis technology of endohedral fullerenes such as Fe@C60 has developed with an electron cyclotron resonance (ECR) ion source. The production of N@C60 was reported. However, the yield was quite low, since most fullerene molecules were broken in the ECR plasma. We have adopted gas-mixing techniques in order to cool the plasma and then reduce fullerene dissociation. Mass spectra of ion beams extracted from fullerene-He, Ar or Xe mixed plasmas were observed with a Faraday cup. From the results, the He gas mixing technique is effective against fullerene destruction.

Asaji, T; Uchida, T; Minezaki, H; Ishihara, S; Racz, R; Muramatsu, M; Biri, S; Kitagawa, A; Kato, Y; Yoshida, Y

2015-01-01T23:59:59.000Z

242

Status of the Bio-Nano electron cyclotron resonance ion source at Toyo University  

E-Print Network [OSTI]

In the paper, the material science experiments, carried out recently using the Bio-Nano electron cyclotron resonance ion source (ECRIS) at Toyo University, are reported. We have investigated several methods to synthesize endohedral C60 using ion-ion and ion-molecule collision reaction in the ECRIS. Because of the simplicity of the configuration, we can install a large choice of additional equipment in the ECRIS. The Bio-Nano ECRIS is suitable not only to test the materials production but also to test technical developments to improve or understand the performance of an ECRIS.

Uchida, T; Ishihara, S; Muramatsu, M; Racz, R; Asaji, T; Kitagawa, A; Kato, Y; Biri, S; Drentje, A G; Yoshida, Y

2015-01-01T23:59:59.000Z

243

Design and testing of an electron cyclotron resonance heating ion source for use in high field compact superconducting cyclotrons  

E-Print Network [OSTI]

The main goal of this project is to evaluate the feasibility of axial injection of a high brightness beam from an Electron Cyclotron Resonance ion source into a high magnetic field cyclotron. Axial injection from an ion ...

Artz, Mark E

2012-01-01T23:59:59.000Z

244

Initiation of a low-pressure glow discharge in a plasma electron source with a ribbon beam  

Science Journals Connector (OSTI)

Results are presented from an experimental investigation of a low-pressure glow discharge with a wedge-shaped hollow cathode in a plasma electron source, where this discharge is initiated by reflex...

V. Ya. Martens

1999-07-01T23:59:59.000Z

245

The electron distribution function in flowing afterglow argon plasma with the D.C. discharge plasma source  

Science Journals Connector (OSTI)

The measurements presented in this paper show that in our experimental conditions, in the flowing afterglow plasma generated by the D.C. plasma source the electron distribution function is not Maxwellian in the ....

J. Glosík; J. Pavlík; M. Šícha

1983-01-01T23:59:59.000Z

246

Estimation of the electron density and radiative energy losses in a calcium plasma source based on an electron cyclotron resonance discharge  

SciTech Connect (OSTI)

The parameters of a calcium plasma source based on an electron cyclotron resonance (ECR) discharge were calculated. The analysis was performed as applied to an ion cyclotron resonance system designed for separation of calcium isotopes. The plasma electrons in the source were heated by gyrotron microwave radiation in the zone of the inhomogeneous magnetic field. It was assumed that, in such a combined trap, the energy of the extraordinary microwave propagating from the high-field side was initially transferred to a small group of resonance electrons. As a result, two electron components with different transverse temperatures-the hot resonance component and the cold nonresonance component-were created in the plasma. The longitudinal temperatures of both components were assumed to be equal. The entire discharge space was divided into a narrow ECR zone, where resonance electrons acquired transverse energy, and the region of the discharge itself, where the gas was ionized. The transverse energy of resonance electrons was calculated by solving the equations for electron motion in an inhomogeneous magnetic field. Using the law of energy conservation and the balance condition for the number of hot electrons entering the discharge zone and cooled due to ionization and elastic collisions, the density of hot electrons was estimated and the dependence of the longitudinal temperature T{sub e Parallel-To} of the main (cold) electron component on the energy fraction {beta} lost for radiation was obtained.

Potanin, E. P., E-mail: potanin@imp.kiae.ru; Ustinov, A. L. [National Research Centre Kurchatov Institute (Russian Federation)

2013-06-15T23:59:59.000Z

247

GEOPHYSICAL RESEARCH LETTERS, VOL. 25, NO. 12, PAGES 2069-2072, JUNE 15, 1998 FAST observations of electron distributions within AKR source  

E-Print Network [OSTI]

of electron distributions within AKR source regions. G.T. Delory, R.E. Ergun, C.W. Carlson, L. Muschietti, C. Observations of high-time resolution 3-D electron distri- butions within the source regions of Auroral growth. The source of the electron instability appears to come from several fea- tures

California at Berkeley, University of

248

arXiv:1004.1985v1[cond-mat.mes-hall]12Apr2010 Current correlations of an on-demand electron source as an  

E-Print Network [OSTI]

arXiv:1004.1985v1[cond-mat.mes-hall]12Apr2010 Current correlations of an on-demand electron source to characterize an on-demand electron source consisting of a quantum dot connected to a conductor via a tunable of the electron emission time, which we call quantum jitter. In optimum op- erating conditions of the source

Plaçais, Bernard

249

Harmonic content of electron-impact source functions in inductively coupled plasmas using an ``on-the-fly'' Monte Carlo technique  

E-Print Network [OSTI]

Harmonic content of electron-impact source functions in inductively coupled plasmas using an ``on of electron-impact source functions having high-threshold energies due to modulation of the tail the time dependence of electron-impact source functions in low-pressure ICP systems. We found that even

Kushner, Mark

250

Experiment study of an electron cyclotron resonant ion source based on a tapered resonance cavity  

SciTech Connect (OSTI)

Electron cyclotron resonant plasma is one type of magnetised plasma generated by continuous microwave energy. It has the property of high degree of ionization and large volume at low gas pressure, which makes it useful for space propulsion and material processing. This article presents the experiment study of the plasma properties and ion beam extraction from an electron cyclotron resonant ion source based on a tapered resonance cavity. Optical emission spectroscopy based on a simple collisional radiation model was used for plasma diagnosis. Experiment results show that, at microwave power setting ranging from 7.06 to 17.40 W and mass flow rate ranging from 1 to 10 sccm, argon gas can be ionized. Ion beam of 109.1 mA from the ion source can be extracted at microwave power of 30 W, mass flow rate of 10 sccm, and accel voltage of 800 V. The diagnosed plasma temperature and density are 2.4–5.2 eV and 2 × 10{sup 16}–4.8 × 10{sup 17} m{sup ?3}, respectively.

Yang, Juan; Shi, Feng; Jin, Yizhou; Wang, Yunmin [College of Astronautics, Northwestern Polytechnic University, Xi'an, Shaanxi 710072 (China)] [College of Astronautics, Northwestern Polytechnic University, Xi'an, Shaanxi 710072 (China); Komurasaki, Kimiya [Department of Aeronautics and Astronautics, The University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-8656 (Japan)] [Department of Aeronautics and Astronautics, The University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-8656 (Japan)

2013-12-15T23:59:59.000Z

251

Development of Polarized Electron Source of GaAs-AlGaAs Superlattice and Strained GaAs  

Science Journals Connector (OSTI)

At Nagoya University, we have continued the development of GaAs polarized electron source (PES) for several years. Our test ... a gun producing (1–5) KeV polarized electrons and a standard 100 KeV Mott polarimete...

T. Nakanishi; S. Nakamura

1991-01-01T23:59:59.000Z

252

Design and dosimetric characteristics of a new endocavitary contact radiotherapy system using an electronic brachytherapy source  

SciTech Connect (OSTI)

Purpose: To present design aspects and acceptance tests performed for clinical implementation of electronic brachytherapy treatment of early stage rectal adenocarcinoma. A dosimetric comparison is made between the historically used Philips RT-50 unit and the newly developed Axxent{sup Registered-Sign} Model S700 electronic brachytherapy source manufactured by Xoft (iCad, Inc.). Methods: Two proctoscope cones were manufactured by ElectroSurgical Instruments (ESI). Two custom surface applicators were manufactured by Xoft and were designed to fit and interlock with the proctoscope cones from ESI. Dose rates, half value layers (HVL), and percentage depth dose (PDD) measurements were made with the Xoft system and compared to historical RT-50 data. A description of the patient treatment approach and exposure rates during the procedure is also provided. Results: The electronic brachytherapy system has a lower surface dose rate than the RT-50. The dose rate to water on the surface from the Xoft system is approximately 2.1 Gy/min while the RT-50 is 10-12 Gy/min. However, treatment times with Xoft are still reasonable. The HVLs and PDDs between the two systems were comparable resulting in similar doses to the target and to regions beyond the target. The exposure rate levels around a patient treatment were acceptable. The standard uncertainty in the dose rate to water on the surface is approximately {+-}5.2%. Conclusions: The Philips RT-50 unit is an out-of-date radiotherapy machine that is no longer manufactured with limited replacement parts. The use of a custom-designed proctoscope and Xoft surface applicators allows delivery of a well-established treatment with the ease of a modern radiotherapy device. While the dose rate is lower with the use of Xoft, the treatment times are still reasonable. Additionally, personnel may stand farther away from the Xoft radiation source, thus potentially reducing radiation exposure to the operator and other personnel.

Richardson, Susan; Garcia-Ramirez, Jose; Lu Wei; Myerson, Robert J.; Parikh, Parag [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States); Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201 (United States); Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States)

2012-11-15T23:59:59.000Z

253

This handout is a short guide for citing commonly used electronic sources using Modern Language Association (MLA) style. For additional information, consult the MLA Handbook for  

E-Print Network [OSTI]

This handout is a short guide for citing commonly used electronic sources using Modern Language. Below are examples of bibliographic entries for electronic sources. Consistency is essential. Note. When citing, you must give the reader enough information to locate the source. In MLA style, sources

254

Improved charge breeding efficiency of light ions with an electron cyclotron resonance ion source  

SciTech Connect (OSTI)

The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a {sup 252}Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficiencies of both gaseous and solid species including 14.7% for the radioactive species {sup 143}Ba{sup 27+}. In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for {sup 23}Na{sup 7+} and 17.9% for {sup 39}K{sup 10+} were obtained injecting stable Na{sup +} and K{sup +} beams from a surface ionization source.

Vondrasek, R.; Kutsaev, Sergey [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Delahaye, P.; Maunoury, L. [Grand Accelerateur National d'Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, Blvd Henri Becquerel, 14076 Caen (France)

2012-11-15T23:59:59.000Z

255

Towards a better comprehension of plasma formation and heating in high performances electron cyclotron resonance ion sources (invited)  

SciTech Connect (OSTI)

Further improvements of electron cyclotron resonance ion sources (ECRIS) output currents and average charge state require a deep understanding of electron and ion dynamics in the plasma. This paper will discuss the most recent advances about modeling of non-classical evidences like the sensitivity of electron energy distribution function to the magnetic field detuning, the influence of plasma turbulences on electron heating and ion confinement, the coupling between electron and ion dynamics. All these issues have in common the non-homogeneous distribution of the plasma inside the source: the abrupt density drop at the resonance layer regulates the heating regimes (from collective to turbulent), the beam formation mechanism and emittance. Possible means to boost the performances of future ECRIS will be proposed. In particular, the use of Bernstein waves, in preliminary experiments performed at Laboratori Nazionali del Sud (LNS) on MDIS (microwave discharge ion sources)-type sources, has permitted to sustain largely overdense plasmas enhancing the warm electron temperature, which will make possible in principle the construction of sources for high intensity multicharged ions beams with simplified magnetic structures.

Mascali, D.; Gammino, S.; Celona, L.; Ciavola, G. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy)

2012-02-15T23:59:59.000Z

256

Young-Type Experiment Using a Single-Electron Source and an Independent Atomic-Size Two-Center Interferometer  

Science Journals Connector (OSTI)

Evidence is given for Young-type interferences caused by a single electron acting on a given double-center scatterer analogous to an atomic-size double-slit system. The electron is provided by autoionization of a doubly excited He atom following the capture of the electrons of H2 by a He2+ incoming ion. The autoionizing projectile is a single-electron source, independent of the interferometer provided by the two H+ centers of the fully ionized H2 molecule. This experiment resembles the famous thought experiment imagined by Feynman in 1963, in which the quantum nature of the electron is illustrated from a Young-like double-slit experiment. Well-defined oscillations are visible in the angular distribution of the scattered electrons, showing that each electron interferes with itself.

J.-Y. Chesnel; A. Hajaji; R. O. Barrachina; F. Frémont

2007-03-08T23:59:59.000Z

257

A Proposal for a Novel H{sup -} Ion Source Based on Electron Cyclotron Resonance Plasma Heating and Surface Ionization  

SciTech Connect (OSTI)

A design for a novel H{sup -} ion source based on electron cyclotron resonance plasma heating and surface ionization is presented. The plasma chamber of the source is an rf-cavity designed for TE{sub 111} eigenmode at 2.45 GHz. The desired mode is excited with a loop antenna. The ionization process takes place on a cesiated surface of a biased converter electrode. The H{sup -} ion beam is further ''self-extracted'' through the plasma region. The magnetic field of the source is optimized for plasma generation by electron cyclotron resonance heating, and beam extraction. The design features of the source are discussed in detail and the attainable H{sup -} ion current, beam emittance and duty factor of the novel source are estimated.

Tarvainen, O.; Kurennoy, S. [Los Alamos National Laboratory, Los Alamos, New Mexico, 87545 (United States)

2009-03-12T23:59:59.000Z

258

A proposal for a novel H ion source based on electron cyclotron resonance heating and surface ionization  

SciTech Connect (OSTI)

A design for a novel H{sup -} ion source based on electron cyclotron resonance plasma heating and surface ionization is presented. The plasma chamber of the source is an rf-cavity designed for TE{sub 111} eigenmode at 2.45 GHz. The desired mode is excited with a loop antenna. The ionization process takes place on a cesiated surface of a biased converter electrode. The H{sup -} ion beam is further 'self-extracted' through the plasma region. The magnetic field of the source is optimized for plasma generation by electron cyclotron resonance heating, and beam extraction. The design features of the source are discussed in detail and the attainable H{sup -} ion current, beam emittance and duty factor of the novel source are estimated.

Tarvainen, Ollie A [Los Alamos National Laboratory; Kurennoy, Sergey [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

259

Advanced light ion source extraction system for a new electron cyclotron resonance ion source geometry at Saclay  

SciTech Connect (OSTI)

One of the main goal of intense light ion injector projects such as IPHI, IFMIF, or SPIRAL2, is to produce high current beams while keeping transverse emittance as low as possible. To prevent emittance growth induced in a dual solenoid low energy transfer line, its length has to be minimized. This can be performed with the advanced light ion source extraction system concept that we are developing: a new ECR 2.45 GHz type ion source based on the use of an additional low energy beam transport (LEBT) short length solenoid close to the extraction aperture to create the resonance in the plasma chamber. The geometry of the source has been considerably modified to allow easy maintenance of each component and to save space in front of the extraction. The source aims to be very flexible and to be able to extract high current ion beams at energy up to 100 kV. A specific experimental setup for this source is under installation on the BETSI test bench, to compare its performances with sources developed up to now in the laboratory, such as SILHI, IFMIF, or SPIRAL2 ECR sources. This original extraction source concept is presented, as well as electromagnetic simulations with OPERA-2D code. Ion beam extraction in space charge compensation regime with AXCEL, and beam dynamics simulation with SOLMAXP codes show the beam quality improvement at the end of the LEBT.

Delferriere, O.; Gobin, R.; Harrault, F.; Nyckees, S.; Sauce, Y.; Tuske, O. [Commissariat a l'Energie Atomique, CEA/Saclay, DSM/IRFU, 91191 Gif/Yvette (France)

2012-02-15T23:59:59.000Z

260

Lifetime measurement of metastable fluorine atoms using electron cyclotron resonance plasma source  

SciTech Connect (OSTI)

The authors have measured the lifetime of metastable state (3s {sup 4}P{sub 5/2}) of F atoms by resonant laser-induced fluorescence method. For this experiment, a special 2.45 GHz electron cyclotron resonance (ECR) plasma source, which is highly efficient in F radical generation and free from magnetic field leakage in front of the beam-emitting orifice, has been developed. Using the ECR plasma gun, the authors observed a precision fluorescence spectrum related to 3p {sup 4}D{sub 7/2}{sup 0}(F=4){yields}3s {sup 4}P{sub 5/2}(F=3) transition of F radicals, which made it possible to experimentally determine the longitudinal velocity distribution and the angular spread of the F radical beam. Based on these measured beam characteristics, the authors extracted a true decay curve of fluorescence intensity as a function of distance from the source and determined the lifetime of F metastable state (3s {sup 4}P{sub 5/2}) as 7.3{+-}0.5 {mu}s.

Shimizu, Masao; Ohmi, Hiromasa; Kakiuchi, Hiroaki; Yasutake, Kiyoshi [Yasu Semiconductor Corporation, 686-1 Ichimiyake, Yasu-cho, Yasu-gun, Shiga 520-2632 (Japan); Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2006-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Experiments with biased side electrodes in electron cyclotron resonance ion sources  

E-Print Network [OSTI]

The output of highly charged ions from an electron cyclotron resonance ion source (ECRIS) consists of ionic losses from a highly confined plasma. Therefore, an increase of the output of the ions of interest always is a compromise between an increase in the confinement and an increase of the losses.One route towards a solution consists of attacking the losses in directions (i.e., radial directions) that do not contribute to the required output. This was demonstrated in an experiment (using the Kei ECRIS at NIRS, Japan) where radial losses were electrostatically reduced by positively biasing one set of six side electrodes surrounding the plasma in side-ward directions attached (insulated) to the cylindrical wall of the plasma chamber. Recently new studies were performed in two laboratories using two essentially different ion sources. At the BioNano ECRIS (Toyo University, Japan) various sets of electrodes were used; each of the electrodes could be biased individually. At the Atomki ECRIS (Hungary), one movable,...

Drentje, A G; Uchida, T; Rácz, R; Biri, S

2015-01-01T23:59:59.000Z

262

Comparative analysis of neutron sources produced by low-energy electrons and deuterons for driving subcritical assemblies.  

SciTech Connect (OSTI)

A conceptual design of an accelerator driven subcritical assembly has been developed using the existing accelerators at Kharkov Institute of Physics and Technology (KIPT) in Ukraine. Two different external neutron source options were examined for driving the subcritical assembly. Electrons with energies below 200 MeV and deuterons with energies below 100 MeV were considered. Comparative analysis of these two options is presented and discussed. The Comparative analysis of neutron sources produced by low-energy electrons and deuterons show that: (1) An electron accelerator with electron energy in the range of 150 to 200 MeV is preferred for producing neutron source; (2) The uranium target material produces the highest neutron yield per electron; (3) The uranium target with 100 KW electron beam produces 3.3 x 10{sup 14} n/s; (4) The thermal hydraulics analyses of the uranium target operating with the 100 KW electron beam power satisfy the engineering design requirements; and (5) The peak thermal stresses (secondary stress) is less than the yield strength of the uranium target material.

Naberezhnev, D.; Gohar, Y.; Belch, H.; Duo, J.; Bolshinsky, I. (Nuclear Engineering Division); (INL)

2008-04-10T23:59:59.000Z

263

Printed from AccessScience @ McGraw-Hill (www.AccessScience.com). Copyright 2000, 2001, 2002 The McGraw-Hill Companies. All rights reserved. Any use is subject to the  

E-Print Network [OSTI]

at the website. Laser-driven x-ray sources ver since the invention of the microscope, one of the great trends, which can then be used to convert light to short pulses of x- rays. Electron motion in laser fields physics Physics: Lasers Page 1 of 6Laser-driven x-ray sources 3/14/2003http://www

Umstadter, Donald

264

Direct laser acceleration of electrons in free-space  

E-Print Network [OSTI]

Compact laser-driven accelerators are versatile and powerful tools of unarguable relevance on societal grounds for the diverse purposes of science, health, security, and technology because they bring enormous practicality to state-of-the-art achievements of conventional radio-frequency accelerators. Current benchmarking laser-based technologies rely on a medium to assist the light-matter interaction, which impose material limitations or strongly inhomogeneous fields. The advent of few cycle ultra-intense radially polarized lasers has materialized an extensively studied novel accelerator that adopts the simplest form of laser acceleration and is unique in requiring no medium to achieve strong longitudinal energy transfer directly from laser to particle. Here we present the first observation of direct longitudinal laser acceleration of non-relativistic electrons that undergo highly-directional multi-GeV/m accelerating gradients. This demonstration opens a new frontier for direct laser-driven particle accelerati...

Carbajo, Sergio; Wong, Liang Jie; Miller, R J Dwayne; Kärtner, Franz X

2015-01-01T23:59:59.000Z

265

Analysis of electron energy distribution of an arc-discharge H{sup -} ion source with Monte Carlo simulation  

SciTech Connect (OSTI)

For optimization and accurate prediction of the amount of H{sup -} ion production in negative ion sources, analysis of electron energy distribution function (EEDF) is necessary. We developed a numerical code which analyzes EEDF in the tandem-type arc-discharge source. It is a three-dimensional Monte Carlo simulation code with the effects of cusp, filter, and extraction magnets. Coulomb collision between electrons is treated with Takizuka's model and several inelastic collisions are treated with null-collision method. We applied this code to the JAEA 10 ampere negative ion source. The numerical result shows that the order of electron density is in good agreement with experimental results. In addition, the obtained EEDF is qualitatively in good agreement with experimental results.

Fujino, I.; Hatayama, A.; Takado, N.; Inoue, T. [Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522 (Japan); Japan Atomic Energy Agency, 801-1 Mukouyama, Naka 311-0193 (Japan)

2008-02-15T23:59:59.000Z

266

RHESSI HARD X-RAY IMAGING SPECTROSCOPY OF EXTENDED SOURCES AND THE PHYSICAL PROPERTIES OF ELECTRON ACCELERATION REGIONS IN SOLAR FLARES  

E-Print Network [OSTI]

RHESSI HARD X-RAY IMAGING SPECTROSCOPY OF EXTENDED SOURCES AND THE PHYSICAL PROPERTIES OF ELECTRON of the acceleration region but also allows an empirical study of the physics of electron tran- sport within the source acceleration and propagation of bremsstrahlung- producing electrons in solar flares. The method involves

California at Berkeley, University of

267

Development of ion injection into the BNL test electron beam ion source using a prototype low energy beam transfer switchyard and a hollow  

E-Print Network [OSTI]

Development of ion injection into the BNL test electron beam ion source using a prototype low-to-pulse basis, the BNL RHIC electron beam ion source EBIS will use injection of primary "seed" ions from energy beam transfer switchyard and a hollow cathode ion source ,,abstract...a...,b... E. N. Beebe, J. G

268

Source Apportionment of Heavy Metals in Air Particulate Matter Using Automated Electron Probe Micro Analysis  

Science Journals Connector (OSTI)

Source apportionment of air particulate matter, using receptor ... not well adapted for situations with a complex source composition because of the inherent inability to resolve chemically equivalent sources. Alt...

W. Van Borm; F. Adams

1988-01-01T23:59:59.000Z

269

Electron beam driven alkali metal atom source for loading a magneto-optical trap in a cryogenic environment  

E-Print Network [OSTI]

We present a versatile and compact electron beam driven source for alkali metal atoms, which can be implemented in cryostats. With a heat load of less than 10mW, the heat dissipation normalized to the atoms loaded into the magneto-optical Trap (MOT), is about a factor 1000 smaller than for a typical alkali metal dispenser. The measured linear scaling of the MOT loading rate with electron current observed in the experiments, indicates that electron stimulated desorption is the corresponding mechanism to release the atoms.

S. Haslinger; R. Amsuess; Ch. Koller; C. Hufnagel; N. Lippok; J. Majer; J. Verdu; S. Schneider; J. Schmiedmayer

2010-03-26T23:59:59.000Z

270

Electron source and acceleration regime of a picosecond electron beam in a gas-filled diode with inhomogeneous field  

Science Journals Connector (OSTI)

It is experimentally demonstrated that, upon the application of a subnanosecond high-voltage pulse to the gap of a diode filled with air at atmospheric pressure, a bunch of runaway electrons is formed in a sha...

G. A. Mesyats; V. G. Shpak; S. A. Shunailov; M. I. Yalandin

2008-02-01T23:59:59.000Z

271

Light Well: ATunable Free-Electron Light Source on a Chip K. F. MacDonald,1,* Y. H. Fu,2  

E-Print Network [OSTI]

Light Well: ATunable Free-Electron Light Source on a Chip G. Adamo,1 K. F. MacDonald,1,* Y. H. Fu,2 and surface plasmon-polariton sources [1­5]. Electron- beam-induced radiation emission [6­8] is of particular-emitter displays [12]. The light well belongs to a broad family of free-electron- driven radiation sources wherein

Zheludev, Nikolay

272

ELECTRON FLUX SPECTRAL IMAGING OF SOLAR FLARES THROUGH REGULARIZED ANALYSIS OF HARD X-RAY SOURCE VISIBILITIES  

E-Print Network [OSTI]

ELECTRON FLUX SPECTRAL IMAGING OF SOLAR FLARES THROUGH REGULARIZED ANALYSIS OF HARD X-RAY SOURCE a new method for imaging spectroscopy analysis of hard X-ray emission during solar flares. The method.e., the two-dimensional spatial Fourier transforms of the spectral image) to obtain smoothed (regularized

Piana, Michele

273

Sub-15 nm Photo-electron Source Using a Nano-aperture Integrated with a Nano-antenna  

Science Journals Connector (OSTI)

We propose a nano-scale C-aperture nano-tip photo-electron source with a CsBr photo-cathode. We fabricated the structure and estimated the optical spot available in the CsBr thin film...

Cheng, Yao-Te; Takashima, Yuzuru; Maldonado, Juan R; Scipioni, Larry; Ferranti, David; Pianetta, Piero A; Hesselink, Lambertus; Pease, Roger F

274

14 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 24, NO. 1, JANUARY 2009 Multiple-LoadSource Integration in a Multilevel  

E-Print Network [OSTI]

a power management system among multiple sources and loads having dif- ferent operating voltages. Index- tional dc­dc converter is a key element to provide the power for the electrical drive train in future14 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 24, NO. 1, JANUARY 2009 Multiple

Tolbert, Leon M.

275

Subnanosecond single electron source in the time-domain A. Mah e (1) , F.D. Parmentier (1) , G. F eve (1) , J.-M. Berroir (1) , T. Kontos (1) ,  

E-Print Network [OSTI]

Subnanosecond single electron source in the time-domain A. Mah#19;e (1) , F.D. Parmentier (1) , G of a single electron source similar to single photon sources in optics. On-demand single electron injection requiring accurate synchronization of two coherent single electron sources. We describe here experimental

Recanati, Catherine

276

Single Source Electron Beam Evaporation of Bi-Sr-Ca-Cu-O Thin Films  

Science Journals Connector (OSTI)

A modified electron beam evaporation technique for the deposition of BiSrCaCuO thin films has been developed. In contrast to the conventional hearthed electron beam crucible the design in the present study use...

M. Ghanashyam Krishna; G. K. Muralidhar…

1990-01-01T23:59:59.000Z

277

Noncollisional heating and electron energy distributions in magnetically enhanced inductively coupled and helicon plasma sources  

E-Print Network [OSTI]

region. This enhancement results from noncollisional heating by the axial electric field for electrons­11 The mecha- nisms through which more efficient heating of electrons oc- curs in these systems are not well- teraction mechanism is electron acceleration by the parallel component of the electric field. The heating

Kushner, Mark

278

Development of a compact thermal lithium atom beam source for measurements of electron velocity distribution function anisotropy in electron cyclotron resonance plasmas  

SciTech Connect (OSTI)

The anisotropy of the electron velocity distribution function (EVDF) in plasmas can be deduced from the polarization of emissions induced by anisotropic electron-impact excitation. In this paper, we develop a compact thermal lithium atom beam source for spatially resolved measurements of the EVDF anisotropy in electron cyclotron resonance (ECR) plasmas. The beam system is designed such that the ejected beam has a slab shape, and the beam direction is variable. The divergence and flux of the beam are evaluated by experiments and calculations. The developed beam system is installed in an ECR plasma device with a cusp magnetic field, and the LiI 2s–2p emission (670.8 nm) is observed in low-pressure helium plasma. The two-dimensional distributions of the degree and direction of the polarization in the LiI emission are measured by a polarization imaging system. The evaluated polarization distribution suggests the spatial variation of the EVDF anisotropy.

Nishioka, T.; Shikama, T.; Nagamizo, S.; Fujii, K.; Hasuo, M. [Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Kyoto 615-8540 (Japan)] [Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Kyoto 615-8540 (Japan); Zushi, H. [Research Institute for Applied Mechanics, Kyushu University, Fukuoka 816-8580 (Japan)] [Research Institute for Applied Mechanics, Kyushu University, Fukuoka 816-8580 (Japan); Uchida, M.; Tanaka, H.; Maekawa, T. [Department of Fundamental Energy Science, Graduate School of Energy Science, Kyoto University, Kyoto 606-8502 (Japan)] [Department of Fundamental Energy Science, Graduate School of Energy Science, Kyoto University, Kyoto 606-8502 (Japan); Iwamae, A. [Research Center for Development of Far-Infrared Region, Fukui University, Fukui 910-8507 (Japan)] [Research Center for Development of Far-Infrared Region, Fukui University, Fukui 910-8507 (Japan)

2013-07-15T23:59:59.000Z

279

Simulation and design of an electron beam ion source charge breeder for the californium rare isotope breeder upgrade  

Science Journals Connector (OSTI)

An electron beam ion source (EBIS) will be constructed and used to charge breed ions from the californium rare isotope breeder upgrade (CARIBU) for postacceleration into the Argonne tandem linear accelerator system (ATLAS). Simulations of the EBIS charge breeder performance and the related ion transport systems are reported. Propagation of the electron beam through the EBIS was verified, and the anticipated incident power density within the electron collector was identified. The full normalized acceptance of the charge breeder with a 2 A electron beam, 0.024???mm?mrad for nominal operating parameters, was determined by simulating ion injection into the EBIS. The optics of the ion transport lines were carefully optimized to achieve well-matched ion injection, to minimize emittance growth of the injected and extracted ion beams, and to enable adequate testing of the charge bred ions prior to installation in ATLAS.

Clayton Dickerson; Brahim Mustapha; Alexander Pikin; Sergey Kondrashev; Peter Ostroumov; Anthony Levand; Rick Fischer

2013-02-15T23:59:59.000Z

280

Electronic equilibrium as a function of depth in tissue from Cobalt-60 point source exposures  

E-Print Network [OSTI]

the X- Y plane. The scanning system consists of a light source, focusing system, photosensing detector, and precision computer controlled linear translation tables. A light emitting diode (LED) is the light source for the system. The proportion... the X- Y plane. The scanning system consists of a light source, focusing system, photosensing detector, and precision computer controlled linear translation tables. A light emitting diode (LED) is the light source for the system. The proportion...

Myrick, Jo Ann

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

High-efficiency cross-beam magnetic electron-impact source for improved miniature Mattauch-Herzog mass spectrometer performance  

SciTech Connect (OSTI)

We describe a newly designed cross-beam magnetic electron-impact ion source (CBM-EI). We demonstrate its superiority in comparison with a conventional source (CB-EI) when used with a commercial miniature sector-field-type, non-scanning mass spectrometer featuring Mattauch-Herzog geometry (MH-MS) and a permanent sector-field magnet. This paper clearly shows the value of the CBM-EI for enhancing MH-MS sensitivity. Unlike secondary electron-multiplier type detectors, the pixelated detector (IonCCD Trade-Mark-Sign ) used in the commercial MH-MS has no gain. The MH-MS/IonCCD system is therefore challenged to compete with time-of-flight and quadrupole MS systems due to their higher ion transmissions and detector gains. Using the new CBM-EI, we demonstrate an instrument sensitivity increase of 20-fold to 100-fold relative to the CB-EI-equipped instrument. This remarkable signal increase by the simple addition of the magnet assembly arises from the magnet-induced gyromotion of the thermionic electrons, which vastly increases the effective path length of the electrons through the ionization region, and the collimated nature of the electron flux, which optimizes the ion transmission through the 100-{mu}m object slit of the MH-MS. Some or all of the realized sensitivity increase may be exchanged for an increase in resolution and/or mass range through the use of a narrower object slit, or for a reduction in ion-source pressure to limit quenching. The CBM-EI should facilitate development of a differentially pumped ion source to extend the lifetime of the filament, especially in otherwise intractable applications associated with oxidizing and corrosive samples.

Hadjar, O.; Fowler, W. K. [OI Analytical/CMS Field Products, 2148 Pelham Parkway, Bldg. 400, Pelham, Alabama 35124 (United States)

2012-06-15T23:59:59.000Z

282

Fast-ignition transport studies: Realistic electron source, integrated particle-in-cell and hydrodynamic modeling, imposed magnetic fields  

SciTech Connect (OSTI)

Transport modeling of idealized, cone-guided fast ignition targets indicates the severe challenge posed by fast-electron source divergence. The hybrid particle-in-cell (PIC) code Zuma is run in tandem with the radiation-hydrodynamics code Hydra to model fast-electron propagation, fuel heating, and thermonuclear burn. The fast electron source is based on a 3D explicit-PIC laser-plasma simulation with the PSC code. This shows a quasi two-temperature energy spectrum and a divergent angle spectrum (average velocity-space polar angle of 52 Degree-Sign ). Transport simulations with the PIC-based divergence do not ignite for >1 MJ of fast-electron energy, for a modest (70 {mu}m) standoff distance from fast-electron injection to the dense fuel. However, artificially collimating the source gives an ignition energy of 132 kJ. To mitigate the divergence, we consider imposed axial magnetic fields. Uniform fields {approx}50 MG are sufficient to recover the artificially collimated ignition energy. Experiments at the Omega laser facility have generated fields of this magnitude by imploding a capsule in seed fields of 50-100 kG. Such imploded fields will likely be more compressed in the transport region than in the laser absorption region. When fast electrons encounter increasing field strength, magnetic mirroring can reflect a substantial fraction of them and reduce coupling to the fuel. A hollow magnetic pipe, which peaks at a finite radius, is presented as one field configuration which circumvents mirroring.

Strozzi, D. J.; Tabak, M.; Larson, D. J.; Divol, L.; Kemp, A. J.; Bellei, C.; Marinak, M. M.; Key, M. H. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)

2012-07-15T23:59:59.000Z

283

A Nanometer-Sized Femtosecond Electron Source at 80 MHz Repetition Rate  

Science Journals Connector (OSTI)

We observe multiphoton electron emission from ultrasharp metallic tips illuminated with 7-fs-light pulses. Local field enhancement confines this emission to the tip apex,...

Lienau, Christoph; Ropers, Claus; Solli, Daniel R; Schulz, Claus Peter; Elsaesser, Thomas

284

Electron-atom source as a primary radiometric standard for the EUV spectral region  

Science Journals Connector (OSTI)

A compact, portable radiometric standard for the EUV wavelength region utilizing single photon counting is described. An energetic beam of electrons is passed through a thin atomic or...

Risley, John S; Westerveld, W B

1989-01-01T23:59:59.000Z

285

Accelerator-based neutron source using a cold deuterium target with degenerate electrons  

SciTech Connect (OSTI)

A neutron generator is considered in which a beam of tritons is incident on a hypothetical cold deuterium target with degenerate electrons. The energy efficiency of neutron generation is found to increase substantially with electron density. Recent reports of potential targets are discussed.

Phillips, R. E.; Ordonez, C. A. [Department of Physics, University of North Texas, Denton, Texas 76203 (United States)] [Department of Physics, University of North Texas, Denton, Texas 76203 (United States)

2013-07-15T23:59:59.000Z

286

Time evolution of endpoint energy of Bremsstrahlung spectra and ion production from an electron cyclotron resonance ion source  

SciTech Connect (OSTI)

Electron cyclotron resonance ion sources (ECRIS) are used to produce high charge state heavy ion beams for the use of nuclear and materials science, for instance. The most powerful ECR ion sources today are superconducting. One of the problems with superconducting ECR ion sources is the use of high radio frequency (RF) power which results in bremsstrahlung radiation adding an extra heat load to the cryostat. In order to understand the electron heating process and timescales in the ECR plasma, time evolution measurement of ECR bremsstrahlung was carried out. In the measurements JYFL 14 GHz ECRIS was operated in a pulsed mode and bremsstrahlung data from several hundred RF pulses was recorded. Time evolution of ion production was also studied and compared to one of the electron heating theories. To analyze the measurement data at C++ program was developed. Endpoint energies of the bremsstrahlung spectra as a function of axial magnetic field strength, pressure and RF power are presented and ion production timescales obtained from the measurements are compared to bremsstrahlung emission timescales and one of the stochastic heating theories.

Tarvainen, Ollie [Los Alamos National Laboratory; Ropponen, Tommi [JYFL; Jones, Peter [JYFL; Kalvas, Taneli [JYFL

2008-01-01T23:59:59.000Z

287

Measurements and modeling of coherent synchrotron radiation and its impact on the Linac Coherent Light Source electron beam  

Science Journals Connector (OSTI)

In order to reach the high peak current required for an x-ray free electron laser, two separate magnetic dipole chicanes are used in the Linac Coherent Light Source accelerator to compress the electron bunch length in stages. In these bunch compressors, coherent synchrotron radiation (CSR) can be emitted either by a short electron bunch or by any longitudinal density modulation that may be on the bunch. In this paper, we report detailed measurements of the CSR-induced energy loss and transverse emittance growth in these compressors. Good agreement is found between the experimental results and multiparticle tracking studies. We also describe direct observations of CSR at optical wavelengths and compare with analytical models based on beam microbunching.

K. L. F. Bane; F.-J. Decker; Y. Ding; D. Dowell; P. Emma; J. Frisch; Z. Huang; R. Iverson; C. Limborg-Deprey; H. Loos; H.-D. Nuhn; D. Ratner; G. Stupakov; J. Turner; J. Welch; J. Wu

2009-03-17T23:59:59.000Z

288

Transmission electron microscopy and Monte Carlo simulations of ordering in Au-Cu clusters produced in a laser vaporization source  

Science Journals Connector (OSTI)

Au-Cu bimetallic alloy clusters are produced in a laser vaporization source starting from Au-Cu alloy targets with different stoichiometric compositions. The clusters are deposited on two different substrates—amorphous carbon and crystalline MgO—and are characterized by electron diffraction and high-resolution electron microscopy. The experiments show that the overall chemical composition in the clusters is the same as the chemical composition of the target material; but the crystal structure of the Au-Cu alloy clusters differs from their known bulk crystal structure. Electron microscopy experiments provide evidence that no chemical ordering exists between Au and Cu atoms and that the clusters are solid solutions. Monte Carlo simulations using the second moment tight-binding approximation, however, predict Cu3Au clusters ordered in the core but with a disordered mantle. The possible origins of the differences between experiment and Monte Carlo simulations are discussed.

B. Pauwels; G. Van Tendeloo; E. Zhurkin; M. Hou; G. Verschoren; L. Theil Kuhn; W. Bouwen; P. Lievens

2001-03-27T23:59:59.000Z

289

Optimization of gas utilization efficiency for short-pulsed electron cyclotron resonance ion source  

SciTech Connect (OSTI)

Numerical analysis of {sup 6}He atoms utilizing efficiency in the ion source with powerful gyrotron heating is performed in present work using zero-dimensional balanced model of ECR discharge in a magnetic trap. Two ways of creation of ion source with high gas utilization efficiency (up to 60%-90%) are suggested.

Izotov, I. V.; Skalyga, V. A.; Zorin, V. G. [Institute of Applied Physics of Russian Academy of Sciences, Nizhny Novgorod (Russian Federation)

2012-02-15T23:59:59.000Z

290

A spatially and temporally localized sub-laser cycle electron source  

Science Journals Connector (OSTI)

We simulate electron emission from a sharp tungsten tip induced by sub-8fs laser pulses and compare DC field and laser power dependence of the emission with experimental results. The simulation shows that with...

Peter Hommelhoff; Catherine Kealhofer; Mark A. Kasevich

2007-01-01T23:59:59.000Z

291

High-repetition Rate Wakefield Electron Source Driven by Few-millijoule Ultrashort Laser Pulses  

Science Journals Connector (OSTI)

10 mJ ultrafast laser pulses acting on gas flow from capillary nozzles generate stable 100 keV electron beams at 500 Hz. Particle-in-cell simulations indicate that slow high amplitude...

He, Zhaohan; Hou, Bixue; Easter, James; Krushelnick, Karl; Nees, John A; Thomas, Alexander

292

Metal boiling under the action of an electron-beam heat source  

Science Journals Connector (OSTI)

The dynamics of vapor bubble growth in a metal alloy under the action of a volume heat source are considered. The possibility of existence of a threshold superheating value below which the boiling process is i...

G. E. Gorelik; A. S. Lerman; N. V. Pavlyukevich…

1975-10-01T23:59:59.000Z

293

Negative-ion mass spectra obtained with the aid of an electron-impact source  

Science Journals Connector (OSTI)

The negative-ion mass spectra of six natural compounds of various classes, obtained with the use of an EI ion source, have been characterized. The conditions for ... presuppose the occurrence of a process of seco...

Ya. V. Rashkes

1993-05-01T23:59:59.000Z

294

The preliminary tests of the superconducting electron cyclotron resonance ion source DECRIS-SC2  

SciTech Connect (OSTI)

A new compact version of the ''liquid He-free'' superconducting ECR ion source, to be used as an injector of highly charged heavy ions for the MC-400 cyclotron, is designed and built at the Flerov Laboratory of Nuclear Reactions in collaboration with the Laboratory of High Energy Physics of JINR. The axial magnetic field of the source is created by the superconducting magnet and the NdFeB hexapole is used for the radial plasma confinement. The microwave frequency of 14 GHz is used for ECR plasma heating. During the first tests, the source shows a good enough performance for the production of medium charge state ions. In this paper, we will present the design parameters and the preliminary results with gaseous ions.

Efremov, A.; Bekhterev, V.; Bogomolov, S.; Loginov, V.; Lebedev, A.; Yazvitsky, N.; Yakovlev, B. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Moscow reg., Dubna 141980 (Russian Federation); Drobin, V. [Veksler and Baldin Laboratory of High Energy Physics, Joint Institute for Nuclear Research, Moscow reg., Dubna 141980 (Russian Federation)

2012-02-15T23:59:59.000Z

295

Accelerated Electrons as the Source of Auroral Kilometric Radiation R. J. Strangeway  

E-Print Network [OSTI]

for Atmospheric and Space Physics University of Colorado, Boulder, CO 80303, USA C. W. Carlson, J. P. McFadden, G the density cavity it is likely that the hot electrons carry most, if not all, of the plasma density. The AKR generated by the earth's auroral zone. First observed as ~ 1 MHz extra-terrestrial noise by Beneditkov et al

Strangeway, Robert J.

296

The electron distribution and SXT images of a coronal soft X-ray source  

Science Journals Connector (OSTI)

The soft X-ray emission may be thermal or non-thermal. The fact that the rise time remains constant as a function of energy points to the same acceleration process for electrons from 2 to 100 keV. For either ... ...

J. M. McTiernan; S. R. Kane; J. M. Loran

1991-01-01T23:59:59.000Z

297

Comparison between off-resonance and electron Bernstein waves heating regime in a microwave discharge ion source  

SciTech Connect (OSTI)

A microwave discharge ion source (MDIS) operating at the Laboratori Nazionali del Sud of INFN, Catania has been used to compare the traditional electron cyclotron resonance (ECR) heating with an innovative mechanisms of plasma ignition based on the electrostatic Bernstein waves (EBW). EBW are obtained via the inner plasma electromagnetic-to-electrostatic wave conversion and they are absorbed by the plasma at cyclotron resonance harmonics. The heating of plasma by means of EBW at particular frequencies enabled us to reach densities much larger than the cutoff ones. Evidences of EBW generation and absorption together with X-ray emissions due to high energy electrons will be shown. A characterization of the discharge heating process in MDISs as a generalization of the ECR heating mechanism by means of ray tracing will be shown in order to highlight the fundamental physical differences between ECR and EBW heating.

Castro, G.; Di Giugno, R.; Miracoli, R. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Universita degli Studi di Catania, Dipartimento di Fisica e Astronomia, V. S. Sofia 64, 95123 Catania (Italy); Mascali, D. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); CSFNSM, Viale A. Doria 6, 95125 Catania (Italy); Romano, F. P. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); CNR-IBAM Via Biblioteca 4, 95124 Catania (Italy); Celona, L.; Gammino, S.; Lanaia, D.; Ciavola, G. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Serafino, T. [CSFNSM, Viale A. Doria 6, 95125 Catania (Italy); Di Bartolo, F. [Universita di Messina, Ctr. da Papardo-Sperone, 98100 Messina (Italy); Gambino, N. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Universita degli Studi di Catania, Dipartimento di Fisica e Astronomia, V. S. Sofia 64, 95123 Catania (Italy); IET-Institute of Energy Technology, LEC-Laboratory for Energy Conversion, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich (Switzerland)

2012-02-15T23:59:59.000Z

298

Plasma studies on electron cyclotron resonance light ion source at CEA/Saclay  

SciTech Connect (OSTI)

By the 90s, the CEA has undertaken to develop the production of intense light ion beams from unconfined ECR plasma. Today, three sources for IPHI, SPIRAL2, and IFMIF projects (respectively, 100 mA of H{sup +}, 8 mA of D{sup +}, and 140 mA of D{sup +}) are installed at CEA/Saclay. In order to improve performances and decrease dimensions of these sources, it is necessary to better understand the mechanisms involved in the production and extraction of particles. As a consequence, theoretical and experimental studies are being carried out. We present a theoretical study based on SOLMAXP, a home-made particle-in-cell code. The aim is to investigate the possibility of reducing the plasma chamber size without loss of beam characteristics. This code has been validated by beam intensity measurements on a permanent magnet based source, producing a proton beam of 30 mA at 40 kV on the test bench BETSI. In order to reduce experimentally the dimensions of plasma chamber, a new source, named ALISES with variable plasma chamber volume, is under assembly.

Nyckees, S.; Delferriere, O.; Duperrier, R.; Harrault, F.; Tuske, O. [CEA/Saclay, DSM/IRFU/SACM/LEDA, F-91191-Gif/Yvette (France)

2012-02-15T23:59:59.000Z

299

A monolithic relativistic electron beam source based on a dielectric laser accelerator structure  

SciTech Connect (OSTI)

Work towards a monolithic device capable of producing relativistic particle beams within a cubic-centimeter is detailed. We will discuss the Micro-Accelerator Platform (MAP), an optical laser powered dielectric accelerator as the main building block of this chip-scale source along with a field enhanced emitter and a region for sub-relativistic acceleration.

McNeur, Josh; Carranza, Nestor; Travish, Gil; Yin Hairong; Yoder, Rodney [UCLA Dept. of Physics and Astronomy, Los Angeles, CA 90095 (United States); College of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610054 (China); Manhattanville College, Physics Dept., 2900 Purchase St., Purchase, NY 10577 (United States)

2012-12-21T23:59:59.000Z

300

Dark matter conversion as a source of boost factor for explaining the cosmic ray positron and electron excesses  

E-Print Network [OSTI]

In interacting multi-component dark matter (DM) models, if the DM components are nearly degenerate in mass and the interactions between them are strong enough, the relatively heavy DM components can be converted into lighter ones at late time after the thermal decoupling. Consequently, the relic density of the lightest DM component can be considerably enhanced at late time. This may contribute to an alternative source of boost factor required to explain the positron and electron excesses reported by the recent DM indirect search experiments such as PAMELA, Fermi-LAT and HESS etc..

Ze-Peng Liu; Yue-Liang Wu; Yu-Feng Zhou

2011-12-17T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Ultrashort Single-Wall Carbon Nanotubes Reveal Field-Emission Coulomb Blockade and Highest Electron-Source Brightness  

Science Journals Connector (OSTI)

We present here well-defined Coulomb staircases using an original field-emission experiment on several individual in situ—grown single-wall carbon nanotubes. A unique in situ process was applied nine times to progressively shorten one single-wall carbon nanotube down to ?10??nm, which increased the oscillations periods from 5.5 to 80 V, the temperature for observable Coulomb staircase to 1100 K and the currents to 1.8???A. This process led to the brightest electron source ever reported [9×1011??A/(str?m2?V)].

A. Pascale-Hamri; S. Perisanu; A. Derouet; C. Journet; P. Vincent; A. Ayari; S.?T. Purcell

2014-03-26T23:59:59.000Z

302

Property-close source separation of hazardous waste and waste electrical and electronic equipment - A Swedish case study  

SciTech Connect (OSTI)

Through an agreement with EEE producers, Swedish municipalities are responsible for collection of hazardous waste and waste electrical and electronic equipment (WEEE). In most Swedish municipalities, collection of these waste fractions is concentrated to waste recycling centres where households can source-separate and deposit hazardous waste and WEEE free of charge. However, the centres are often located on the outskirts of city centres and cars are needed in order to use the facilities in most cases. A full-scale experiment was performed in a residential area in southern Sweden to evaluate effects of a system for property-close source separation of hazardous waste and WEEE. After the system was introduced, results show a clear reduction in the amount of hazardous waste and WEEE disposed of incorrectly amongst residual waste or dry recyclables. The systems resulted in a source separation ratio of 70 wt% for hazardous waste and 76 wt% in the case of WEEE. Results show that households in the study area were willing to increase source separation of hazardous waste and WEEE when accessibility was improved and that this and similar collection systems can play an important role in building up increasingly sustainable solid waste management systems.

Bernstad, Anna, E-mail: anna.bernstad@chemeng.lth.se [Dep. of Chem. Eng., Faculty of Eng., Lund University, Lund (Sweden); Cour Jansen, Jes la [Dep. of Chem. Eng., Faculty of Eng., Lund University, Lund (Sweden); Aspegren, Henrik [VA SYD, City of Malmoe (Sweden)

2011-03-15T23:59:59.000Z

303

Discharge and emission parameters of a plasma electron source based on a discharge in crossed E × H fields with various cathode materials  

Science Journals Connector (OSTI)

A plasma electron source (PES) based on a discharge in...E × H...fields is developed and tested. The working gas is supplied to a quasi-closed PES discharge chamber, in which the conditions for effective ionizati...

A. P. Dostanko; D. A. Golosov

2009-10-01T23:59:59.000Z

304

Tunable Radiation Source by Coupling Laser-Plasma-Generated Electrons to a Periodic Structure  

SciTech Connect (OSTI)

Near-infrared radiation around 1000 nm generated from the interaction of a high-density MeV electron beam, obtained by impinging an intense ultrashort laser pulse on a solid target, with a metal grating is observed experimentally. Theoretical modeling and particle-in-cell simulation suggest that the radiation is caused by the Smith-Purcell mechanism. The results here indicate that tunable terahertz radiation with tens GV/m field strength can be achieved by using appropriate grating parameters.

Jin, Z. [Photon Pioneers Center, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871 (Japan); Chen, Z. L.; Kon, A.; Nakatsutsumi, M. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871 (Japan); Zhuo, H. B. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871 (Japan); School of Science, National University of Defense Technology, Changsha 410073 (China); Wang, H. B.; Zhang, B. H.; Gu, Y. Q.; Wu, Y. C.; Zhu, B.; Wang, L. [National Key Laboratory of Laser Fusion, CAEP, Mianyang 621900 (China); Yu, M. Y. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Institute for Theoretical Physics I, Ruhr University, Bochum D-44780 (Germany); Sheng, Z. M. [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Kodama, R. [Photon Pioneers Center, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871 (Japan); Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871 (Japan); Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka, 565-0871 (Japan)

2011-12-23T23:59:59.000Z

305

Runaway electrons as a source of impurity and reduced fusion yield in the dense plasma focus  

Science Journals Connector (OSTI)

Impurities produced by the vaporization of metals in the electrodes may be a major cause of reduced fusion yields in high-current dense plasma focus devices. We propose here that a major but hitherto-overlooked cause of such impurities is vaporization by runaway electrons during the breakdown process at the beginning of the current pulse. This process is sufficient to account for the large amount of erosion observed in many dense plasma focus devices on the anode very near to the insulator. The erosion is expected to become worse with lower pressures typical of machines with large electrode radii and would explain the plateauing of fusion yield observed in such machines at higher peak currents. Such runaway electron vaporization can be eliminated by the proper choice of electrode material by reducing electrode radii and thus increasing fill gas pressure or by using pre-ionization to eliminate the large fields that create runaway electrons. If these steps are combined with monolithic electrodes to eliminate arcing erosion large reductions in impurities and large increases in fusion yield may be obtained as the I4 scaling is extended to higher currents.

2014-01-01T23:59:59.000Z

306

Electron Injector Studies at LBL  

E-Print Network [OSTI]

Measurements at the SLC Electron Source", J.Sodja, M.J.great interested in bright electron sources because they areintensity brighter electron sources that the conventional

Kim, C.H.

2010-01-01T23:59:59.000Z

307

P. W. Guilbert, A. C. Fabian and Susan Stepney. Electron-ion coupling in rapidly varying sources. Monthly Notices of the Royal Astronomical Society, 199:19P-21P, 1982.  

E-Print Network [OSTI]

P. W. Guilbert, A. C. Fabian and Susan Stepney. Electron-ion coupling in rapidly varying sources- temperature, high-efficiency sources. 2. The efficiency limit and electron-ion coupling The maximum luminosity is the minimum value of te, the time-scale on which most photons can escape from the source. Ignoring electron

Stepney, Susan

308

FAST observations of electron distributions within AKR source G.T. Delory, R.E. Ergun, C.W. Carlson, L. Muschetti, C.C. Chaston, W. Peria, and J.P.  

E-Print Network [OSTI]

1 FAST observations of electron distributions within AKR source regions. G.T. Delory, R.E. Ergun, C the source regions of Auroral Kilometric Radiation (AKR) are reported. In general, the electron data display stabilized by AKR wave growth. The source of the electron instability appears to come from several features

Strangeway, Robert J.

309

Measurements of Linac4 H Ion Source Beam with a Magnetized Einzel Lens Electron Dump  

E-Print Network [OSTI]

Linac4 is a part of the upgrade of CERN’s accelerator complex for increased luminosity in the LHC. A new system to extract the ion beam from the plasma generator has been designed and tested, in order to improve the reliability and beam optics of the pulsed H- ion source. This paper presents the successfully implemented extraction system and three different beam measurements. The simulations compare well to the measurements and show that the plasma density was too low for the extraction system design during the measurements.

Midttun, O; Scrivens, R

2013-01-01T23:59:59.000Z

310

Electron  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to measure the electron density gradient and its fluctuations. Two separate laser beams with slight spatial offset and frequency difference are coupled into a single mixer...

311

Ideas for Future Synchrotron Light Sources  

E-Print Network [OSTI]

of very-high-brightness electron sources, it is anticipatedcharacteristics for the electron source, given in u_ble 1.Table 1 Electron Source Characteristics Characteristic f

Jackson, A.

2011-01-01T23:59:59.000Z

312

Conceptual design of first toroidal electron cyclotron resonance ion source and modeling of ion extraction from it  

E-Print Network [OSTI]

Electron Cyclotron Resonance Ion Sources (ECRIS) progressed to higher and higher ion currents and charge states by adopting stronger magnetic fields (beneficial for confinement) and proportionally higher ECR frequencies. Further improvements would require the attainment of "triple products" of density, temperature and confinement time comparable with major fusion experiments. For this, we propose a new, toroidal rather than linear, ECRIS geometry, which would at the same time improve confinement and make better use of the magnetic field. Ion extraction is more complicated than from a linear device, but feasible, as our modelling suggests: single-particle tracings showed successful extraction by at least two techniques, making use respectively of a magnetic extractor and of ExB drifts. Additional techniques are briefly discussed.

Caliri, C; Volpe, F A

2015-01-01T23:59:59.000Z

313

Electron  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electron thermal transport within magnetic islands in the reversed-field pinch a... H. D. Stephens, 1,b D. J. Den Hartog, 1,3 C. C. Hegna, 1,2 and J. A. Reusch 1 1 Department of...

314

X-ray spectroscopy of warm and hot electron components in the CAPRICE source plasma at EIS testbench at GSI  

SciTech Connect (OSTI)

An experimental campaign aiming to detect X radiation emitted by the plasma of the CAPRICE source – operating at GSI, Darmstadt – has been carried out. Two different detectors (a SDD – Silicon Drift Detector and a HpGe – hyper-pure Germanium detector) have been used to characterize the warm (2–30 keV) and hot (30–500 keV) electrons in the plasma, collecting the emission intensity and the energy spectra for different pumping wave frequencies and then correlating them with the CSD of the extracted beam measured by means of a bending magnet. A plasma emissivity model has been used to extract the plasma density along the cone of sight of the SDD and HpGe detectors, which have been placed beyond specific collimators developed on purpose. Results show that the tuning of the pumping frequency considerably modifies the plasma density especially in the warm electron population domain, which is the component responsible for ionization processes: a strong variation of the plasma density near axis region has been detected. Potential correlations with the charge state distribution in the plasma are explored.

Mascali, D., E-mail: davidmascali@lns.infn.it; Celona, L.; Castro, G.; Torrisi, G.; Neri, L.; Gammino, S.; Ciavola, G. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy)] [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy); Maimone, F.; Maeder, J.; Tinschert, K.; Spaedtke, K. P.; Rossbach, J.; Lang, R. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany)] [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany); Romano, F. P. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy) [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy); IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); Musumarra, A.; Altana, C.; Caliri, C. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy) [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, via S. Sofia 64, 95123 Catania (Italy)

2014-02-15T23:59:59.000Z

315

Electron  

Science Journals Connector (OSTI)

Absolute grand total cross sections (TCSs) for electron-disilane (Si2H6) scattering have been measured over the energy range from 1 to 370 eV in a linear transmission experiment. The low-energy TCS is dominated by a broad resonant-like enhancement. In the region of the maximum the present grand TCS values appeared to be distinctly lower than previously reported integral elastic cross section data. A comparison of total electron scattering cross sections for the two simplest silicon hydrides and relevant hydrocarbons is given.

Czeslaw Szmytkowski; Pawel Mozejko; Grzegorz Kasperski

2001-01-01T23:59:59.000Z

316

Fast ignition: Dependence of the ignition energy on source and target parameters for particle-in-cell-modelled energy and angular distributions of the fast electrons  

SciTech Connect (OSTI)

The energy and angular distributions of the fast electrons predicted by particle-in-cell (PIC) simulations differ from those historically assumed in ignition designs of the fast ignition scheme. Using a particular 3D PIC calculation, we show how the ignition energy varies as a function of source-fuel distance, source size, and density of the pre-compressed fuel. The large divergence of the electron beam implies that the ignition energy scales with density more weakly than the ?{sup ?2} scaling for an idealized beam [S. Atzeni, Phys. Plasmas 6, 3316 (1999)], for any realistic source that is at some distance from the dense deuterium-tritium fuel. Due to the strong dependence of ignition energy with source-fuel distance, the use of magnetic or electric fields seems essential for the purpose of decreasing the ignition energy.

Bellei, C.; Divol, L.; Kemp, A. J.; Key, M. H.; Larson, D. J.; Strozzi, D. J.; Marinak, M. M.; Tabak, M.; Patel, P. K. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)

2013-05-15T23:59:59.000Z

317

Temporal synchronization of GHz repetition rate electron and laser pulses for the optimization of a compact inverse-Compton scattering x-ray source  

E-Print Network [OSTI]

The operation of an inverse-Compton scattering source of x-rays or gamma-rays requires the precision alignment and synchronization of highly focused electron bunches and laser pulses at the collision point. The arrival times of electron and laser pulses must be synchronized with picosecond precision. We have developed an RF synchronization technique that reduces the initial timing uncertainty from 350 ps to less than 2 ps, greatly reducing the parameter space to be optimized while commissioning the x-ray source. We describe the technique and present measurements of its performance.

Hadmack, Michael R; Madey, John M J; Kowalczyk, Jeremy M D

2014-01-01T23:59:59.000Z

318

Effect of the energy spectrum of an electron source on the attraction of the electrons into the accelerating mode in a betatron  

Science Journals Connector (OSTI)

The energy spread of the electrons in a betatron has a stabilizing influence on the motion of the beam at all stages of the accelerating cycle. The possibility of electrons with a variety of energies being cap...

V. V. Evstigneev; G. V. Milyutin

1974-06-01T23:59:59.000Z

319

Ion source  

DOE Patents [OSTI]

A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species.

Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA)

1984-01-01T23:59:59.000Z

320

Virtual anode as a source of low-frequency oscillations of a high-current electron beam  

Science Journals Connector (OSTI)

We have studied the transport of a relativistic electron beam with supercritical current in a cylindrical drift chamber in the presence of an ion flux. A theoretical analysis of the electron-ion flux dynamics ...

1 P. I. Markov; I. N. Onishchenko; G. V. Sotnikov

2003-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Interatomic Coulombic Decay as a New Source of Low Energy Electrons in slow Ion-Dimer Collisions  

E-Print Network [OSTI]

We provide the experimental evidence that the single electron capture process in slow collisions between O$^{3+}$ ions and neon dimer targets leads to an unexpected production of low-energy electrons. This production results from the interatomic Coulombic decay process, subsequent to inner shell single electron capture from one site of the neon dimer. Although pure one-electron capture from inner shell is expected to be negligible in the low collision energy regime investigated here, the electron production due to this process overtakes by one order of magnitude the emission of Auger electrons by the scattered projectiles after double-electron capture. This feature is specific to low charge states of the projectile: similar studies with Xe$^{20+}$ and Ar$^{9+}$ projectiles show no evidence of inner shell single-electron capture. The dependence of the process on the projectile charge state is interpreted using simple calculations based on the classical over the barrier model.

Iskandar, W; Leredde, A; Flechard, X; Gervais, B; Guillous, S; Hennecart, D; Mery, A; Rangama, J; Zhou, C L; Shiromaru, H; Cassimi, A

2014-01-01T23:59:59.000Z

322

Electronic  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

contribution contribution to friction on GaAs: An atomic force microscope study Yabing Qi, 1,2 J. Y. Park, 2 B. L. M. Hendriksen, 2 D. F. Ogletree, 2 and M. Salmeron 2,3 1 Applied Science and Technology Graduate Group, University of California, Berkeley, California 94720, USA 2 Materials Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA 3 Department of Materials Sciences and Engineering, University of California, Berkeley, California 94720, USA ͑Received 23 January 2008; revised manuscript received 11 April 2008; published 7 May 2008͒ The electronic contribution to friction at semiconductor surfaces was investigated by using a Pt-coated tip with 50 nm radius in an atomic force microscope sliding against an n-type GaAs͑100͒ substrate. The GaAs surface was covered by an approximately 1 nm thick oxide layer. Charge accumulation

323

2D electron density profile measurement in tokamak by laser-accelerated ion-beam probe  

SciTech Connect (OSTI)

A new concept of Heavy Ion Beam Probe (HIBP) diagnostic has been proposed, of which the key is to replace the electrostatic accelerator of traditional HIBP by a laser-driven ion accelerator. Due to the large energy spread of ions, the laser-accelerated HIBP can measure the two-dimensional (2D) electron density profile of tokamak plasma. In a preliminary simulation, a 2D density profile was reconstructed with a spatial resolution of about 2 cm, and with the error below 15% in the core region. Diagnostics of 2D density fluctuation is also discussed.

Chen, Y. H.; Yang, X. Y.; Lin, C., E-mail: linchen0812@pku.edu.cn, E-mail: cjxiao@pku.edu.cn; Wang, X. G.; Xiao, C. J., E-mail: linchen0812@pku.edu.cn, E-mail: cjxiao@pku.edu.cn [State Key Lab of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Wang, L. [Institute of Physics, Chinese Academy of Sciences, P. O. Box 603, Beijing 100190 (China); Xu, M. [Center for Fusion Science of Southwestern Institute of Physics, P. O. Box 432, Chengdu 610041 (China)

2014-11-15T23:59:59.000Z

324

Laser Plasma Particle Accelerators: Large Fields for Smaller Facility Sources  

E-Print Network [OSTI]

of high- gradient, laser plasma particle accelerators.accelerators that use laser-driven plasma waves. Theseleft) showing the laser (red), plasma wake density (purple-

Geddes, Cameron G.R.

2010-01-01T23:59:59.000Z

325

Optically pulsed electron accelerator  

DOE Patents [OSTI]

An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

Fraser, J.S.; Sheffield, R.L.

1985-05-20T23:59:59.000Z

326

Optically pulsed electron accelerator  

DOE Patents [OSTI]

An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

Fraser, John S. (Los Alamos, NM); Sheffield, Richard L. (Los Alamos, NM)

1987-01-01T23:59:59.000Z

327

Design and testing of an electron cyclotron resonance heating ion source for use in high field compact superconducting cyclotrons .  

E-Print Network [OSTI]

??The main goal of this project is to evaluate the feasibility of axial injection of a high brightness beam from an Electron Cyclotron Resonance ion… (more)

Artz, Mark E

2012-01-01T23:59:59.000Z

328

On forbidden high-energy electrons as a source of background in X-ray and gamma-ray observations  

E-Print Network [OSTI]

The study is devoted to a problem of electron-induced contaminant to X-ray and gamma-ray astrophysical measurements on board low-orbiting satellites. We analyzed enhancements of electron fluxes in energy range 100 - 300 keV observed at equatorial and low latitudes by a fleet of NOAA/POES low-orbiting satellites over the time period from 2003 to 2005. It was found that 100-300 keV electron fluxes in the forbidden zone below the inner radiation belt enhanced by several orders of magnitude during geomagnetic storms and/or under strong compressions of the magnetosphere. The enhancements are related to high substorm activity and occurred at any local time. Intense fluxes of the energetic electrons in the forbidden zone can be considered as an essential contaminant to X-ray and gamma-ray measurements at low-latitude and low-altitude orbits.

Suvorova, Alla V

2014-01-01T23:59:59.000Z

329

Electron storage ring BESSY as a radiometric source of calculable spectral radiant power between 0.5 and 1000 nm  

Science Journals Connector (OSTI)

The spectral radiant power of the electron storage ring BESSY was measured absolutely in the infrared and visible, and its angular distribution in the infrared, visible, and soft-x-ray...

Riehle, F; Wende, B

1985-01-01T23:59:59.000Z

330

Electron Beam Source Molecular Beam Epitaxy of AlxGal?xAs Graded Band Gap Device Structures  

Science Journals Connector (OSTI)

A new method has been developed for the growth of graded band-gap AlxGal?xAs alloys by molecular beam epitaxy which is based upon electron. beam evaporation of the Group III elements ... . The large dynamic respo...

R. J. Malik; A. F. J. Levi; B. F. Levine…

1989-01-01T23:59:59.000Z

331

A SOURCE OF COHERENT SOFT X-RAY RADIATION BASED ON HIGH-ORDER HARMONIC GENERATION AND FREE ELECTRON  

E-Print Network [OSTI]

at shorter wavelengths down to 4 nm is obtained by bunching the energy modulated electrons and passing ultraviolet (EUV) (see [1] and references therein). The repetition rate of these pulses depends been demon- strated with a repetition rate of the order of 1 kHz. Higher pulse energies have also been

Wurtele, Jonathan

332

Combining dark matter detectors and electron-capture sources to hunt for new physics in the neutrino sector  

E-Print Network [OSTI]

In this letter we point out the possibility to study new physics in the neutrino sector using dark matter detectors based on liquid xenon. These are characterized by very good spatial resolution and extremely low thresholds for electron recoil energies. When combined with a radioactive $\

Coloma, Pilar; Link, Jonathan M

2014-01-01T23:59:59.000Z

333

Beam dynamics study of a 30?MeV electron linear accelerator to drive a neutron source  

SciTech Connect (OSTI)

An experimental neutron facility based on 32?MeV/18.47?kW electron linac has been studied by means of PARMELA simulation code. Beam dynamics study for a traveling wave constant gradient electron accelerator is carried out to reach the preferential operation parameters (E?=?30?MeV, P?=?18?kW, dE/E?electron energy is required to produce acceptable neutron flux. The final neutron flux is estimated to be 5?×?10{sup 11}?n/cm{sup 2}/s/mA. Future development will be the real design of a 30?MeV electron linac based on S band traveling wave.

Kumar, Sandeep; Yang, Haeryong; Kang, Heung-Sik, E-mail: hskang@postech.ac.kr [Pohang Accelerator Laboratory, San31, Hyoja-dong, Pohang, Gyeongbuk 790-784 (Korea, Republic of)

2014-02-14T23:59:59.000Z

334

890 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 21, NO. 4, JULY 2006 A Self-Adjusting Sinusoidal Power Source  

E-Print Network [OSTI]

Mordechai Peretz Abstract--A new self-adjusting current-fed push­pull parallel inverter (SA the amplitude, waveform and efficiency of the power driver. The current-fed push­pull resonant inverter (CFPPRI890 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 21, NO. 4, JULY 2006 A Self-Adjusting Sinusoidal

335

FLASH Code, Development and Applications: an Open Source Tool for HEDP |  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

FLASH Code, Development and Applications: an Open Source Tool for HEDP FLASH Code, Development and Applications: an Open Source Tool for HEDP Event Sponsor: Computation Institute Presentation Start Date: Dec 19 2013 - 12:30pm Building/Room: SEARLE 240A, 5735 S. Ellis Avenue - This talk will be broadcast via Adobe Connect (see below) Location: University of Chicago Speaker(s): Petros Tzeferacos Speaker(s) Title: University of Chicago Host: Don Lamb In this talk I will present recent and future developments of FLASH, an open source, multi-physics, finite-volume, shock capturing code with a broad range of capabilities. The code has recently been extended to tackle high-energy physics (HEDP) problems, such as laser-driven laboratory experiments, transforming it into a powerful tool for the HEDP community, both in academia and national labs. I will discuss the implementation and

336

194 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 56, NO. 1, JANUARY 2009 PWM Method to Eliminate Power Sources in a  

E-Print Network [OSTI]

to Eliminate Power Sources in a Nonredundant 27-Level Inverter for Machine Drive Applications Mauricio Rotella-stage 27-level inverter using "H" converters is analyzed for medium- and high-power machine drive was implemented using DSP controllers, which give flexibility to the system. Index Terms--Drives, multilevel

Catholic University of Chile (Universidad Católica de Chile)

337

IEEE ELECTRON DEVICE LETTERS, VOL. 25, NO. 8, AUGUST 2004 565 N-Type Schottky Barrier Source/Drain MOSFET  

E-Print Network [OSTI]

-aligned rare earth metal-(Erbium, Terbium, Dys- prosium) silicided Schottky junctions. Index Terms/Drain MOSFET Using Ytterbium Silicide Shiyang Zhu, Member, IEEE, Jingde Chen, M.-F. Li, Senior Member, IEEE, S--Ytterbium silicide, for the first time, was used to form the Schottky barrier source/drain (S/D) of N-channel MOSFETs

Fu, Li Ming

338

Ion sources with arc-discharge plasma box driven by directly heated LaB{sub 6} electron emitter or cold cathode (invited)  

SciTech Connect (OSTI)

In the Budker Institute, Novosibirsk, an ion source with arc-discharge plasma box has been developed in the recent years for application in thermonuclear devices for plasma diagnostics. Several modifications of the ion source were provided with extracted current ranging from 1 to 7 A and pulse duration of up to 4 s. Initially, the arc-discharge plasma box with cold cathode was used, with which pulse duration is limited to 2 s by the cathode overheating and sputtering in local arc spots. Recently, a directly heated LaB{sub 6} electron emitter was employed instead, which has extended lifetime compared to the cold cathode. In the paper, characteristics of the beam produced with both arrangements of the plasma box are presented.

Ivanov, Alexander A.; Davydenko, Vladimir I.; Deichuli, Petr P.; Shulzhenko, Grigori I.; Stupishin, Nikolay V. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation)

2008-02-15T23:59:59.000Z

339

Quantitative experiments with electrons in a positively charged Beam  

E-Print Network [OSTI]

analyzer, and the gas electron source diagnostic (GESD) tocommissioned the Gas-Electron Source Diagnostic (GESD) tosources. Each type of electron source can therefor affect an

2006-01-01T23:59:59.000Z

340

Atomic Resolution Imaging with a sub-50 pm Electron Probe  

E-Print Network [OSTI]

of the demagnified electron source, respectively. Previousfinite size of the electron source, thus implying infinitethe finite size of the electron source using the geometrical

Erni, Rolf P.

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Controlled Electron Injection into Plasma Accelerators and Space Charge Estimates  

E-Print Network [OSTI]

5.8.1 Compact electron sources . . . . .are capable of producing electron sources which are ultra-of compact high energy electron source. The use of plasma as

Fubiani, Gwenael J.

2005-01-01T23:59:59.000Z

342

Transport and Non-Invasive Position Detection of Electron Beams from Laser-Plasma Accelerators  

E-Print Network [OSTI]

magnets from the electron source through our THUNDERa PMQ doublet from the electron source through an undulator.1 mrad rms from the electron source. ELECTRON BEAM TRANSPORT

Osterhoff, Jens

2012-01-01T23:59:59.000Z

343

An Ultra-Bright Pulsed Electron Beam with Low Longitudinal Emittance  

E-Print Network [OSTI]

Abstract Most existing electron sources extract electrons? f ? 2 10 ?3 . An electron source with these parameters canble applications for this electron source include angstrom-

2005-01-01T23:59:59.000Z

344

Numerical Study of Coulomb Scattering Effects on Electron Beam from a Nano-Tip  

E-Print Network [OSTI]

current, high brightness electron source plays a key role incommunity. Low emittance electron source using electronsThe electron current density from this source is about 110

2008-01-01T23:59:59.000Z

345

500 MW X-Band RF System of a 0.25 GeV Electron LINAC for Advanced Compton Scattering Source Application  

SciTech Connect (OSTI)

A Mono-Energetic Gamma-Ray (MEGa-Ray) Compton scattering light source is being developed at LLNL in collaboration with the SLAC National Accelerator Laboratory. The electron beam for the Compton scattering interaction will be generated by a X-band RF gun and a X-band LINAC at the frequency of 11.424 GHz. High power RF in excess of 500 MW is needed to accelerate the electrons to energy of 250 MeV or greater for the interaction. Two high power klystron amplifiers, each capable of generating 50 MW, 1.5 msec pulses, will be the main high power RF sources for the system. These klystrons will be powered by state of the art solid-state high voltage modulators. A RF pulse compressor, similar to the SLED II pulse compressor, will compress the klystron output pulse with a power gain factor of five. For compactness consideration, we are looking at a folded waveguide setup. This will give us 500 MW at output of the compressor. The compressed pulse will then be distributed to the RF gun and to six traveling wave accelerator sections. Phase and amplitude control are located at the RF gun input and additional control points along the LINAC to allow for parameter control during operation. This high power RF system is being designed and constructed. In this paper, we will present the design, layout, and status of this RF system.

Chu, Tak Sum; /LLNL, Livermore; Anderson, Scott; /LLNL, Livermore; Barty, Christopher; /LLNL, Livermore; Gibson, David; /LLNL, Livermore; Hartemann, Fred; /LLNL, Livermore; Marsh, Roark; /LLNL, Livermore; Siders, Craig; /LLNL, Livermore; Adolphsen, Chris; /SLAC; Jongewaard, Erik; /SLAC; Raubenheimer, Tor; /SLAC; Tantawi, Sami; /SLAC; Vlieks, Arnold; /SLAC; Wang, Juwen; /SLAC

2012-07-03T23:59:59.000Z

346

Multicharged ion source based on Penning-type discharge with electron cyclotron resonance heating by millimeter waves  

SciTech Connect (OSTI)

We suggest a Penning-type discharge as a trigger discharge for fast development of pulsed electron cyclotron resonance plasma. The Penning-type discharge glows at a low pressure as needed. Gyrotron radiation (75 GHz, 200 kW, 1 ms) was used for plasma heating. Fully striped helium ions were demonstrated, average charge of ions in the plasma was {approx_equal} 2. Experiment and calculations show that high charge states of heavier gases require lower initial pressure and longer development time. Only moderate charge states are achievable in this pulsed scheme.

Vodopyanov, A. V.; Izotov, I. V.; Mansfeld, D. A. [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Yushkov, G. Yu. [High Current Electronic Institute, Russian Academy of Sciences, Tomsk (Russian Federation)

2012-02-15T23:59:59.000Z

347

Design of a compact, permanent magnet electron cyclotron resonance ion source for proton and H{sub 2}{sup +} beam production  

SciTech Connect (OSTI)

A 2.45 GHz microwave ion source was developed at China Institute of Atomic Energy (CIAE) for proton beam production of over 60 mA [B.-Q. Cui, Y.-W. Bao, L.-Q. Li, W.-S. Jiang, and R.-W. Wang, Proceedings of the High Current Electron Cyclotron Resonance (ECR) Ion Source for Proton Accelerator, APAC-2001, 2001 (unpublished)]. For various proton beam applications, another 2.45 GHz microwave ion source with a compact structure is designed and will be built at CIAE as well for high current proton beam production. It is also considered to be used for the test of H{sub 2}{sup +} beam, which could be injected into the central region model cyclotron at CIAE, and accelerated to 5 MeV before extraction by stripping. The required ECR magnetic field is supplied by all the permanent magnets rather than electrical solenoids and six poles. The magnetic field distribution provided by this permanent magnets configuration is a large and uniformly volume of ECR zone, with central magnetic field of a magnitude of {approx}875 Gs[T. Taylor and J. S. C. Wills, Nucl. Instrum. Methods Phys. Res. A 309, 37 (1991)]. The field adjustment at the extraction end can be implemented by moving the position of the magnet blocks. The results of plasma, coupling with 2.45 GHz microwave in the ECR zone inside the ion source are simulated by particle-in-cell code to optimize the density by adjusting the magnetic field distribution. The design configuration of the ion source will be summarized in the paper.

Jia Xianlu; Zhang Tianjue; Wang Chuan; Zheng Xia; Yin Zhiguo; Zhong Junqing; Wu Longcheng; Qin Jiuchang [China Institute of Atomic Energy, P.O. Box 275(3), Beijing 102413 (China); Luo Shan [The 6th Department, Communication Command Academy, Wuhan 430010 (China)

2010-02-15T23:59:59.000Z

348

From Clark Lake to Chandra: Closing in on the Low End of the Relativistic Electron Spectra in Extragalactic Sources  

E-Print Network [OSTI]

The limited angular resolutions and sensitivities historically available below 300 MHz have made it difficult to define the low end of the electron energy distribution, N(gamma). We extrapolate down from the well observed segments of radio spectra with almost complete ignorance of what N(gamma) is actually doing. We do not know if there is a low energy cutoff or if there are other deviations from extrapolated power laws. The result is that we really do not have a good estimate of the total energy density and pressure of the relativistic plasmas we study. The situation is even worse for Inverse Compton (IC) X-ray emission, several flavors of which rely on electrons of Lorentz factors, gamma, of 1000, 300, or in some cases of order 50. If our assumed extrapolations are wrong, some IC emission models may have to be abandoned. We present several examples and demonstrate that the Long Wave Array (LWA) should have sufficient sensitivity and resolution to obtain meaningful constraints on N(gamma) at low energies.

D. E. Harris

2004-10-20T23:59:59.000Z

349

Comparison of TG-43 and TG-186 in breast irradiation using a low energy electronic brachytherapy source  

SciTech Connect (OSTI)

Purpose: The recently updated guidelines for dosimetry in brachytherapy in TG-186 have recommended the use of model-based dosimetry calculations as a replacement for TG-43. TG-186 highlights shortcomings in the water-based approach in TG-43, particularly for low energy brachytherapy sources. The Xoft Axxent is a low energy (<50 kV) brachytherapy system used in accelerated partial breast irradiation (APBI). Breast tissue is a heterogeneous tissue in terms of density and composition. Dosimetric calculations of seven APBI patients treated with Axxent were made using a model-based Monte Carlo platform for a number of tissue models and dose reporting methods and compared to TG-43 based plans. Methods: A model of the Axxent source, the S700, was created and validated against experimental data. CT scans of the patients were used to create realistic multi-tissue/heterogeneous models with breast tissue segmented using a published technique. Alternative water models were used to isolate the influence of tissue heterogeneity and backscatter on the dose distribution. Dose calculations were performed using Geant4 according to the original treatment parameters. The effect of the Axxent balloon applicator used in APBI which could not be modeled in the CT-based model, was modeled using a novel technique that utilizes CAD-based geometries. These techniques were validated experimentally. Results were calculated using two dose reporting methods, dose to water (D{sub w,m}) and dose to medium (D{sub m,m}), for the heterogeneous simulations. All results were compared against TG-43-based dose distributions and evaluated using dose ratio maps and DVH metrics. Changes in skin and PTV dose were highlighted. Results: All simulated heterogeneous models showed a reduced dose to the DVH metrics that is dependent on the method of dose reporting and patient geometry. Based on a prescription dose of 34 Gy, the average D{sub 90} to PTV was reduced by between ?4% and ?40%, depending on the scoring method, compared to the TG-43 result. Peak skin dose is also reduced by 10%–15% due to the absence of backscatter not accounted for in TG-43. The balloon applicator also contributed to the reduced dose. Other ROIs showed a difference depending on the method of dose reporting. Conclusions: TG-186-based calculations produce results that are different from TG-43 for the Axxent source. The differences depend strongly on the method of dose reporting. This study highlights the importance of backscatter to peak skin dose. Tissue heterogeneities, applicator, and patient geometries demonstrate the need for a more robust dose calculation method for low energy brachytherapy sources.

White, Shane A.; Landry, Guillaume; Reniers, Brigitte, E-mail: brigitte.reniers@maastro.nl [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN (Netherlands)] [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN (Netherlands); Fonseca, Gabriel Paiva [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Instituto de Pesquisas Energéticas e Nucleares – IPEN-CNEN/SP, São Paulo CP 11049, 05422-970 (Brazil)] [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Instituto de Pesquisas Energéticas e Nucleares – IPEN-CNEN/SP, São Paulo CP 11049, 05422-970 (Brazil); Holt, Randy; Rusch, Thomas [Xoft, A Subsidiary of iCAD, Sunnyvale, California 94085-4115 (United States)] [Xoft, A Subsidiary of iCAD, Sunnyvale, California 94085-4115 (United States); Beaulieu, Luc [Centre Hospitalier Universitaire de Québec Université Laval, Radio-Oncologie et Centre de Recherche en Cancérologie de l’Université Laval, Québec, Québec G1R 2J6 Canada (Canada)] [Centre Hospitalier Universitaire de Québec Université Laval, Radio-Oncologie et Centre de Recherche en Cancérologie de l’Université Laval, Québec, Québec G1R 2J6 Canada (Canada); Verhaegen, Frank [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Department of Oncology, McGill University, Montreal, Quebec H3G 1A4 (Canada)] [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Department of Oncology, McGill University, Montreal, Quebec H3G 1A4 (Canada)

2014-06-15T23:59:59.000Z

350

Radiation source  

DOE Patents [OSTI]

A device and method for relativistic electron beam heating of a high-density plasma in a small localized region. A relativistic electron beam generator or accelerator produces a high-voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low-density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high-density target plasma which typically comprises DT, DD, or similar thermonuclear gas at a density of 10.sup.17 to 10.sup.20 electrons per cubic centimeter. The target gas is ionized prior to application of the relativistic electron beam by means of a laser or other preionization source to form a plasma. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 MeV, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy into a small localized region of the high-density plasma target.

Thode, Lester E. (Los Alamos, NM)

1981-01-01T23:59:59.000Z

351

Conversion of the energy-subtracted CT number to electron density based on a single linear relationship: an experimental verification using a clinical dual-source CT scanner  

Science Journals Connector (OSTI)

In radiotherapy treatment planning, the conversion of the computed tomography (CT) number to electron density is one of the main processes that determine the accuracy of patient dose calculations. However, in general, the CT number and electron density of tissues cannot be interrelated using a simple one-to-one correspondence. This study aims to experimentally verify the clinical feasibility of an existing novel conversion method proposed by the author of this note, which converts the energy-subtracted CT number (?HU) to the relative electron density (?e) via a single linear relationship by using a dual-energy CT (DECT). The ?HU–?e conversion was performed using a clinical second-generation dual-source CT scanner operated in the dual-energy mode with tube potentials of 80 kV and 140 kV with and without an additional tin filter. The ?HU–?e calibration line was obtained from the DECT image acquisition for tissue substitutes in an electron density phantom. In addition, the effect of object size on ?HU–?e conversion was also experimentally investigated. The plot of the measured ?HU versus nominal ?e values exhibited a single linear relationship over a wide ?e range from 0.00 (air) to 2.35 (aluminum). The ?HU–?e conversion performed with the tin filter yielded a lower dose and more reliable ?e values that were less affected by the object-size variation when compared to the corresponding values obtained for the case without the tin filter.

Masayoshi Tsukihara; Yoshiyuki Noto; Takahide Hayakawa; Masatoshi Saito

2013-01-01T23:59:59.000Z

352

Quasi-monoenergetic Electron Beams from Laser-plasma Acceleration by Ionization-induced Injection in Low- density Pure Nitrogen  

E-Print Network [OSTI]

We report a laser wakefield acceleration of electron beams up to 130 MeV from laser-driven 4-mm long nitrogen gas jet. By using a moderate laser intensity (3.5*10^18 W.cm^(-2) ) and relatively low plasma densities (0.8*10^18 cm^(-3) to 2.7*10^18 cm^(-3)) we have achieved a stable regime for laser propagation and consequently a stable generation of electron beams. We experimentally studied the dependence of the drive laser energy on the laser-plasma channel and electron beam parameters. The quality of the generated electron beams is discussed within the framework of the ionization-induced injection mechanism.

Tao, Mengze; Li, Song; Mirzaie, Mohammad; Chen, Liming; He, Fei; Cheng, Ya; Zhang, Jie

2014-01-01T23:59:59.000Z

353

Simulating Electron Clouds in Heavy-Ion Accelerators  

E-Print Network [OSTI]

three different types of electron sources - direct electronELECTRON CLOUD SHAPE ON ELECTRON SOURCE TYPE W e describe in on the nature of the electron source. T h e first case we

2005-01-01T23:59:59.000Z

354

Dependence of ion beam current on position of mobile plate tuner in multi-frequencies microwaves electron cyclotron resonance ion source  

SciTech Connect (OSTI)

We are constructing a tandem-type electron cyclotron resonance ion source (ECRIS). The first stage of this can supply 2.45 GHz and 11-13 GHz microwaves to plasma chamber individually and simultaneously. We optimize the beam current I{sub FC} by the mobile plate tuner. The I{sub FC} is affected by the position of the mobile plate tuner in the chamber as like a circular cavity resonator. We aim to clarify the relation between the I{sub FC} and the ion saturation current in the ECRIS against the position of the mobile plate tuner. We obtained the result that the variation of the plasma density contributes largely to the variation of the I{sub FC} when we change the position of the mobile plate tuner.

Kurisu, Yosuke; Kiriyama, Ryutaro; Takenaka, Tomoya; Nozaki, Dai; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2012-02-15T23:59:59.000Z

355

Progress on the Construction of the 100 MeV / 100 kW Electron Linac for the NSC KIPT Neutron Source  

E-Print Network [OSTI]

IHEP, China is constructing a 100 MeV / 100 kW electron Linac for NSC KIPT, Ukraine. This linac will be used as the driver of a neutron source based on a subcritical assembly. In 2012, the injector part of the accelerator was pre-installed as a testing facility in the experimental hall #2 of IHEP. The injector beam and key hardware testing results were met the design goal. Recently, the injector testing facility was disassembled and all of the components for the whole accelerator have been shipped to Ukraine from China by ocean shipping. The installation of the whole machine in KIPT will be started in June, 2013. The construction progress, the design and testing results of the injector beam and key hardware are presented.

Yun-Long, Chi; Guo-Xi, Pei; Shu-Hong, Wang; Jian-She, Cao; Mi, Hou; Wei-Bin, Liu; Zu-Sheng, Zhou; Feng-Li, Zhao; Rong, Liu; Xiang-Cheng, Kong; Jing-Xia, Zhao; Chang-Dong, Deng; Hong, Song; Jin-Tong, Liu; Xu-Wen, Dai; Jun-Hui, Yue; Qi, Yang; Da-Yong, He; Xiang, He; Qi, Le; Xiao-Ping, Li; Lin, Wang; Xiang-Jian, Wang; Hui-Zhou, Ma; Xiao-Yan, Zhao; Yan-Feng, Sui; Hai-Sheng, Guo; Chuang-Xin, Ma; Jian-Bing, Zhao; Peng, Chen

2013-01-01T23:59:59.000Z

356

A gas-jet transport and catcher technique for on-line production of radioactive ion beams using an electron cyclotron resonance ion-source  

SciTech Connect (OSTI)

Radioactive ion beams (RIB) have been produced on-line, using a gas-jet recoil transport coupled Electron Cyclotron Resonance (ECR) ion-source at the VECC-RIB facility. Radioactive atoms/molecules carried through the gas-jet were stopped in a catcher placed inside the ECR plasma chamber. A skimmer has been used to remove bulk of the carrier gas at the ECR entrance. The diffusion of atoms/molecules through the catcher has been verified off-line using stable isotopes and on-line through transmission of radioactive reaction products. Beams of {sup 14}O (71 s), {sup 42}K (12.4 h), {sup 43}K (22.2 h), and {sup 41}Ar (1.8 h) have been produced by bombarding nitrogen and argon gas targets with proton and alpha particle beams from the K130 cyclotron at VECC. Typical measured intensity of RIB at the separator focal plane is found to be a few times 10{sup 3} particles per second (pps). About 3.2 Multiplication-Sign 10{sup 3} pps of 1.4 MeV {sup 14}O RIB has been measured after acceleration through a radiofrequency quadrupole linac. The details of the gas-jet coupled ECR ion-source and RIB production experiments are presented along with the plans for the future.

Naik, V.; Chakrabarti, A.; Bhattacharjee, M.; Karmakar, P.; Bandyopadhyay, A.; Dechoudhury, S.; Mondal, M.; Pandey, H. K.; Lavanyakumar, D.; Mandi, T. K.; Dutta, D. P.; Kundu Roy, T.; Bhowmick, D.; Sanyal, D.; Srivastava, S. C. L.; Ray, A.; Ali, Md. S. [Variable Energy Cyclotron Centre (VECC), Sector-1, Block-AF, Bidhan Nagar, Kolkata 700064 (India); Bhattacharjee, S. [UGC-DAE CSR, Kolkata Centre, III/LB-8, Bidhan Nagar, Kolkata 700098 (India)

2013-03-15T23:59:59.000Z

357

Simultaneous usage of pinhole and penumbral apertures for imaging small scale neutron sources from inertial confinement fusion experiments  

SciTech Connect (OSTI)

Inertial confinement fusion experiments at the National Ignition Facility are designed to understand the basic principles of creating self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic capsules. The neutron imaging diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by observing neutron images in two different energy bands for primary (13-17 MeV) and down-scattered (6-12 MeV) neutrons. From this, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. These experiments provide small sources with high yield neutron flux. An aperture design that includes an array of pinholes and penumbral apertures has provided the opportunity to image the same source with two different techniques. This allows for an evaluation of these different aperture designs and reconstruction algorithms.

Guler, N.; Volegov, P.; Danly, C. R.; Grim, G. P.; Merrill, F. E.; Wilde, C. H. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States)

2012-10-15T23:59:59.000Z

358

R&D for a Soft X-Ray Free Electron Laser Facility  

E-Print Network [OSTI]

Quantum-degenerate Electron Source, Physical Review LettersHigh brightness electron source, beam instrumentation andFEL Requires high rep-rate electron source Beam switchyard

Staples, John

2009-01-01T23:59:59.000Z

359

Electrons and gas versus high brightness ion beams  

E-Print Network [OSTI]

Review 1/11/05 beam Gas-Electron Source Diagnostic (GESD)and mitigation Gas-electron source diagnostic (GESD) [beam Measure each source of electrons Measure electron

2005-01-01T23:59:59.000Z

360

STUDIES OF ELECTRON CORRELATION IN THE PHOTOIONIZATION PROCESS  

E-Print Network [OSTI]

Kr. Another drawback of the electron source is that it needs1) to act as an electron source. ample room for improvement.UV lamp can be used as an electron source in electron impact

Roseberg, Richard Allen

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Design of scaled electronic devices based on III-V materials  

E-Print Network [OSTI]

94 Electron-Electron Scattering …………………………………….99 Sourceconsiders the electrons within the source as classical gas.lifetime of the electron in the source For an infinitesimal

Wang, Lingquan

2009-01-01T23:59:59.000Z

362

PUBLISHED ONLINE: 19 AUGUST 2012 | DOI: 10.1038/NPHYS2390 Dynamics of relativistic transparency and optical  

E-Print Network [OSTI]

accelerators, X-ray sources and techniques for controlling the shape and contrast of intense laser pulses. W opaque to laser light. However, when the light is of sufficient intensity to drive electrons-overdense regime of relativistic plasmas, which should be useful in the development of laser-driven particle

Loss, Daniel

363

Influence of the longitudinal magnetic field in the accelerating gap on the limiting parameters of a plasma electron source operating in the forevacuum pressure range  

Science Journals Connector (OSTI)

Results are presented from experimental studies of the influence of the longitudinal magnetic field in the accelerating gap on the emission current, accelerating voltage, and maximum gas pressure in a plasma electron

I. S. Zhirkov; V. A. Burdovitsin; E. M. Oks

2007-09-01T23:59:59.000Z

364

Adapting High Brightness Relativistic Electron Beams for Ultrafast Science  

E-Print Network [OSTI]

Comparison of x-ray and electron sources for structuralJ. Luiten. Ultracold electron source. Phys. Rev. Lett. , 95:to non-relativistic electron sources is an inter- esting

Scoby, Cheyne Matthew

2012-01-01T23:59:59.000Z

365

Selective ion source  

DOE Patents [OSTI]

A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P{sup +} from PH{sub 3}. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P{sup +}, As{sup +}, and B{sup +} without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices. 6 figs.

Leung, K.N.

1996-05-14T23:59:59.000Z

366

Selective ion source  

DOE Patents [OSTI]

A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P.sup.+ from PH.sub.3. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P.sup.+, AS.sup.+, and B.sup.+ without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices.

Leung, Ka-Ngo (Hercules, CA)

1996-01-01T23:59:59.000Z

367

Feasibility study of a laser ion source for primary ion injection into the Relativistic Heavy Ion Collider electron beam ion sourcea...  

E-Print Network [OSTI]

Collider electron beam ion sourcea... Takeshi Kanesue Department of Applied Quantum Physics and Nuclear Okamura Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973, USA are in the vacuum of about 10-4 Pa and are isolated from the rest of the beam line to allow the extraction of ions

368

Analytical Model for Rates of Electron Attachment and Intramolecular Electron Transfer in Electron Transfer  

E-Print Network [OSTI]

. As a result, in ECD the primary source of excess energy is the recombination energy released when the electronAnalytical Model for Rates of Electron Attachment and Intramolecular Electron Transfer in Electron-mail: simons@chem.utah.edu Abstract: A new physical model is put forth to allow the prediction of electron

Simons, Jack

369

Sinterable powders from laser driven reactions : final report  

E-Print Network [OSTI]

Extremely fine, uniform ceramic powders have been synthesized from Sil4 NH3 and C2H4 gas phase reactants that are heated by absorbing optical energy emitted from a C02 laser. Resulting Si, Si3N4 and SiC powders have been ...

Haggerty, John Scarseth

1981-01-01T23:59:59.000Z

370

Ion Sources - Cyclotron  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sources Sources The 88-Inch Cyclotron is fed by three Electron Cyclotron Resonance (ECR) high-charge-state ion sources, the ECR, the AECR, and VENUS, currently the most powerful ECR ion source in the world. Built to answer the demand for intense heavy ion beams, these high performance ion sources enable the 88-Inch Cyclotron to accelerate beams of ions from hydrogen to uranium. The ECR ion sources allow the efficient use of rare isotopes of stable elements, either from natural or enriched sources. A variety of metallic ion beams are routinely produced in our low temperature oven (up to 600°C) and our high temperature oven (up to 2100°C). Furthermore, the ability to produce "cocktails" (mixtures of beams) for the Berkeley Accelerator Space Effects (BASE) Facility adds tremendously to the flexibility of the 88-Inch Cyclotron.

371

Terahertz radiation as a bunch diagnostic for laser-wakefield-accelerated electron bunches  

SciTech Connect (OSTI)

Experimental results are reported from two measurement techniques (semiconductor switching and electro-optic sampling) that allow temporal characterization of electron bunches produced by a laser-driven plasma-based accelerator. As femtosecond electron bunches exit the plasma-vacuum interface, coherent transition radiation (at THz frequencies) is emitted. Measuring the properties of this radiation allows characterization of the electron bunches. Theoretical work on the emission mechanism is presented, including a model that calculates the THz wave form from a given bunch profile. It is found that the spectrum of the THz pulse is coherent up to the 200 {micro}m thick crystal (ZnTe) detection limit of 4 THz, which corresponds to the production of sub-50 fs (rms) electron bunch structure. The measurements demonstrate both the shot-to-shot stability of bunch parameters that are critical to THz emission (such as total charge and bunch length), as well as femtosecond synchronization among bunch, THz pulse, and laser beam.

van Tilborg, Jeroen; Schroeder, Carl; Filip, Catalin; Toth, Csaba; Geddes, Cameron; Fubiani, Gwenael; Esarey, Eric; Leemans, Wim

2011-06-17T23:59:59.000Z

372

Negative ion source  

DOE Patents [OSTI]

A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reeccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200.degree. to 500.degree. for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

Delmore, James E. (Idaho Falls, ID)

1987-01-01T23:59:59.000Z

373

Profiles of ion beams and plasma parameters on a multi-frequencies microwaves large bore electron cyclotron resonance ion source with permanent magnets  

SciTech Connect (OSTI)

In order to contribute to various applications of plasma and beams based on an electron cyclotron resonance, a new concept on magnetic field with all magnets on plasma production and confinement has been proposed with enhanced efficiency for broad and dense ion beam. The magnetic field configuration consists of a pair of comb-shaped magnet surrounding plasma chamber cylindrically. Resonance zones corresponding for 2.45 GHz and 11-13 GHz frequencies are positioned at spatially different positions. We launch simultaneously multiplex frequencies microwaves operated individually, try to control profiles of the plasma parameters and the extracted ion beams, and to measure them in detail.

Kato, Yushi; Sakamoto, Naoki; Kiriyama, Ryutaro; Takenaka, Tomoya; Kurisu, Yosuke; Nozaki, Dai; Sato, Fuminobu; Iida, Toshiyuki [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

2012-02-15T23:59:59.000Z

374

EFFECT OF A MAGNETIC FILTER ON HYDROGEN ION SPECIES IN A MULTICUSP ION SOURCE  

E-Print Network [OSTI]

16 eV) primary electrons into the source plasma chamber.return the primary electrons to the source chamber, positiveenergetic electrons and is therefore the ion source chamber

Ehlers, K.W.

2014-01-01T23:59:59.000Z

375

Compact x-ray source and panel  

DOE Patents [OSTI]

A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

Sampayon, Stephen E. (Manteca, CA)

2008-02-12T23:59:59.000Z

376

Magnetic Order in Kondo-Lattice Systems due to Electron-Electron Interactions  

E-Print Network [OSTI]

source of decoherence of electron spin qubits is the hyperfine coupling of the electron spin the electron spin and lead to the decoherence. This decoherence source can be largely suppressed whenMagnetic Order in Kondo-Lattice Systems due to Electron-Electron Interactions Bernd Braunecker

Braunecker, Bernd

377

Bioavailability of Fe(III) in Loess Sediments: An Important Source...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Bioavailability of Fe(III) in Loess Sediments: An Important Source of Electron Acceptors. Bioavailability of Fe(III) in Loess Sediments: An Important Source of Electron Acceptors....

378

Genesis Electronics | Open Energy Information  

Open Energy Info (EERE)

Solar Product: Technology company, focusing on consumer applications for solar energy and alternative energy sources. References: Genesis Electronics1 This article is a stub. You...

379

Two-frequency heating technique at the 18 GHz electron cyclotron resonance ion source of the National Institute of Radiological Sciences  

E-Print Network [OSTI]

The two-frequency heating technique was studied to increase the beam intensities of highly charged ions provided by the high-voltage extraction configuration (HEC) ion source at the National Institute of Radiological Sciences (NIRS). The observed dependences on microwave power and frequency suggested that this technique improved plasma stability but it required precise frequency tuning and more microwave power than was available before 2013. Recently, a new, high-power (1200 W) wide bandwidth (17.1-18.5 GHz) travelling-wave-tube amplifier (TWTA) was installed. After some single tests with klystron and TWT amplifiers the simultaneous injection of the two microwaves has been successfully realized. The dependence of highly charged ions (HCI) currents on the superposed microwave power was studied by changing only the output power of one of the two amplifiers, alternatively. While operating the klystron on its fixed 18.0 GHz, the frequency of the TWTA was swept within its full limits (17.1-18.5 GHz), and the effec...

Biri, S; Muramatsu, M; Drentje, A G; Rácz, R; Yano, K; Kato, Y; Sasaki, N; Takasugi, W

2015-01-01T23:59:59.000Z

380

Source Emissions and Transport  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

electron micrograph image, Lara Gundel with instrumentation electron micrograph image, Lara Gundel with instrumentation Source Emissions and Transport Investigators conduct research here to characterize and better understand the sources of airborne volatile, semi-volatile and particulate organic pollutants in the indoor environment. This research includes studies of the physical and chemical processes that govern indoor air pollutant concentrations and exposures. The motivation is to contribute to the reduction of potential human health effects. Contacts Randy Maddalena RLMaddalena@lbl.gov (510) 486-4924 Mark Mendell MJMendell@lbl.gov (510) 486-5762 Links Pollutant Sources, Dynamics and Chemistry Group Batteries and Fuel Cells Buildings Energy Efficiency Electricity Grid Energy Analysis Energy Technologies Environmental Impacts

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

The components for a quantum computer based on surface state electrons on liquid helium  

E-Print Network [OSTI]

3.2 Electron Sources . . . . . 3.2.1 Porous Silicon . . .Goodkind, J.M. , “An electron source and a single electronbolometer. The electron source is behind the detector, and

Naberhuis, Brian Patrick

2007-01-01T23:59:59.000Z

382

Beam Energy Scaling on Ion-Induced Electron Yield from K+ Impact on Stainless Steel  

E-Print Network [OSTI]

into GESD. FIG. 3. Gas-Electron Source Diagnostic (GESD).data with the Gas-Electron Source Diagnostic (GESD) [15]obtained with Gas-Electron Source Diagnostic at 88 degrees

2006-01-01T23:59:59.000Z

383

Perytons and their Possible Sources  

E-Print Network [OSTI]

Perytons are terrestrial signals that exhibit dispersion measure (DM) similar to pulsars. In trying to identify terrestrial sources of such perytons, investigation into signals from airborne equipment (aircraft), RFI emissions from electronics and lightning phenomenon reveals that the possible sources of perytons could be lightning phenomenon. Narrow Bipolar Pulses (NBPs) and Terrestrial Gamma Flashes (TGFs) are good investigational candidates.

Khan, Mohammad Danish

2014-01-01T23:59:59.000Z

384

Carbon nanotube electron sources and applications  

Science Journals Connector (OSTI)

...Review | 0 Biocompatible Materials 0 Macromolecular Substances...Carbon | Biocompatible Materials chemistry Crystallization...Wang et al. 2001), cathode-ray lamps (Saito...al. 2002) are under active consideration. Present...of carbon and related materials'. Phil. Trans. R...

2004-01-01T23:59:59.000Z

385

Source of electron energy for animal metabolism  

Science Journals Connector (OSTI)

The histochemical localization of ascorbic acid was carried out in the pectoral muscles of various birds using a modified method. — The greater deposition of silver granules within the red fibres as well as in...

N. J. Chinoy

386

Contaminant Sources  

Science Journals Connector (OSTI)

Contaminant sources include almost every component in the manufacturing process: people, materials, processing equipment, and manufacturing environments. People can generate contaminating particles, gases, conden...

Alvin Lieberman

1992-01-01T23:59:59.000Z

387

Electron donor-dependent radionuclide reduction and nanoparticle...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

size were observed, the association of UO2 nanoparticles with an exopolymeric substance (EPS) was observed and found to be independent of electron donor source. Electron...

388

COLLOQUIUM: Exploring the Physical Properties of Matter in Extreme...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and developed into an unlimited carbon-free energy source. Recently, experiments on laser-driven targets have begun on the National Ignition Facility to reach temperatures...

389

Competitive Sourcing  

Broader source: Energy.gov (indexed) [DOE]

COMPETITIVE SOURCING COMPETITIVE SOURCING ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬ Report on Competitive Sourcing Results Fiscal Year 2006 May 2007 Executive Office of the President Office of Management and Budget TABLE OF CONTENTS Executive Summary ...................................................................................... 1 Introduction................................................................................................. 4 I. The big picture ......................................................................................... 4 II. How public-private competition was used in FY 2006 .................................... 6 A. Anticipated benefits from competition in FY 2006

390

Columbia University Varying Electron Cyclotron ResonanceVarying Electron Cyclotron Resonance  

E-Print Network [OSTI]

currently via two electron cyclotron resonance heating (ECRH) sources: 2.5 kW at 2.45 GHz and 2.5 kW at 6 and heated via electron cyclotron resonance heating (ECRH).electron cyclotron resonance heating (ECRHColumbia University Varying Electron Cyclotron ResonanceVarying Electron Cyclotron Resonance

391

Chapter 2 - Energy Sources  

Science Journals Connector (OSTI)

Abstract In today’s industrialized world, energy became vital to all human activities including manufacturing, data processing, heating, cooling, lighting, transportation, food processing, etc., yet it is invisible for most of us. Today’s energy generation technologies are undergoing a paradigm shift; the solution to our current dilemma requires more renewable contribution as well as the more efficient utilization of conventional energy sources. Recognizing this importance, this chapter focuses on energy sources and energy generation technologies including, coal, hydroelectric, nuclear, solar, wind, ocean, and several others. Alternative energy technologies received great interest in recent years due to environmental impact, greenhouse gas emissions, national energy security, and increasing cost of fossil fuel-based sources. With particular emphasis on renewable and alternative energy systems, characteristic features of the renewable energy sources have been reviewed. Since power electronics is a key enabling technology for renewable energy utilization, power electronic converters and interfaces that are used for grid interconnection and stand-alone operation have been presented.

Omer C. Onar; Alireza Khaligh

2015-01-01T23:59:59.000Z

392

Solenoid and monocusp ion source  

DOE Patents [OSTI]

An ion source which generates hydrogen ions having high atomic purity incorporates a solenoidal permanent magnets to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures.

Brainard, John Paul (Albuquerque, NM); Burns, Erskine John Thomas (Albuquerque, NM); Draper, Charles Hadley (Albuquerque, NM)

1997-01-01T23:59:59.000Z

393

Solenoid and monocusp ion source  

DOE Patents [OSTI]

An ion source which generates hydrogen ions having high atomic purity incorporates a solenoidal permanent magnets to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures. 6 figs.

Brainard, J.P.; Burns, E.J.T.; Draper, C.H.

1997-10-07T23:59:59.000Z

394

PUBLISHED ONLINE: 31 JULY 2011 | DOI: 10.1038/NPHYS2052 Arbitrarily shaped high-coherence electron  

E-Print Network [OSTI]

by the thermal nature of conventional electron sources and by divergence due to repulsive interactions between to dynamically shape the electron source itself and to observe this shape in the propagated electron bunch-atom electron source, and the potential for alleviation of electron-source brightness limitations due to Coulomb

Loss, Daniel

395

Competitive Sourcing  

Broader source: Energy.gov (indexed) [DOE]

Competitive Sourcing Competitive Sourcing The Department of Energy's (DOE) Competitive Sourcing program is a management initiative aimed at improving DOE's performance and reducing the Department's operational costs. The program is governed by Office of Management and Budget (OMB) Circular A- 76, Performance of Commercial Activities, dated May 29, 2003. The commercial activities selected for review and competition include functions performed by government employees that are readily available in the private sector, and where the potential for efficiencies, regardless of the winning provider, are highly likely. The candidate functions are chosen from the Department's annual Federal Activities Inventory Reform (FAIR) Act Inventory and subjected to a feasibility review to determine if a prudent business case can be made to enter

396

Intense steady state electron beam generator  

DOE Patents [OSTI]

An intense, steady state, low emittance electron beam generator is formed by operating a hollow cathode discharge plasma source at critical levels in combination with an extraction electrode and a target electrode that are operable to extract a beam of fast primary electrons from the plasma source through a negatively biased grid that is critically operated to repel bulk electrons toward the plasma source while allowing the fast primary electrons to move toward the target in the desired beam that can be successfully transported for relatively large distances, such as one or more meters away from the plasma source.

Hershcovitch, Ady (Mount Sinai, NY); Kovarik, Vincent J. (Bohemia, NY); Prelec, Krsto (Setauket, NY)

1990-01-01T23:59:59.000Z

397

Compton Sources of Electromagnetic Radiation  

SciTech Connect (OSTI)

When a relativistic electron beam interacts with a high-field laser beam, intense and highly collimated electromagnetic radiation will be generated through Compton scattering. Through relativistic upshifting and the relativistic Doppler effect, highly energetic polarized photons are radiated along the electron beam motion when the electrons interact with the laser light. For example, X-ray radiation can be obtained when optical lasers are scattered from electrons of tens-of-MeV beam energy. Because of the desirable properties of the radiation produced, many groups around the world have been designing, building, and utilizing Compton sources for a wide variety of purposes. In this review article, we discuss the generation and properties of the scattered radiation, the types of Compton source devices that have been constructed to date, and the prospects of radiation sources of this general type. Due to the possibilities of producing hard electromagnetic radiation in a device that is small compared to the alternative storage ring sources, it is foreseen that large numbers of such sources may be constructed in the future.

Geoffrey Krafft,Gerd Priebe

2011-01-01T23:59:59.000Z

398

Computer Optimized Design of Electron Guns John David  

E-Print Network [OSTI]

into an electron beam. Electron beam devices include RF sources for numerous applications such as communications design time for a new electron gun for an RF source is 30- 40 man-hours involving 20-30 design iterationsComputer Optimized Design of Electron Guns John David Lawrence Ives Hien Tran Thuc Bui Michael

399

Free electron laser  

DOE Patents [OSTI]

A high gain, single-pass free electron laser formed of a high brilliance electron injector source, a linear accelerator which imparts high energy to the electron beam, and an undulator capable of extremely high magnetic fields, yet with a very short period. The electron injector source is the first stage (gap) of the linear accelerator or a radial line transformer driven by fast circular switch. The linear accelerator is formed of a plurality of accelerating gaps arranged in series. These gaps are energized in sequence by releasing a single pulse of energy which propagates simultaneously along a plurality of transmission lines, each of which feeds the gaps. The transmission lines are graduated in length so that pulse power is present at each gap as the accelerated electrons pass therethrough. The transmission lines for each gap are open circuited at their ends. The undualtor has a structure similar to the accelerator, except that the transmission lines for each gap are substantially short circuited at their ends, thus converting the electric field into magnetic field. A small amount of resistance is retained in order to generate a small electric field for replenishing the electron bunch with the energy lost as it traverses through the undulator structure.

Villa, Francesco (Alameda, CA)

1990-01-01T23:59:59.000Z

400

COMPETITIVE SOURCING  

Broader source: Energy.gov (indexed) [DOE]

COMPETITIVE SOURCING COMPETITIVE SOURCING EXECUTIVE STEERING GROUP MEETING PROCEEDINGS June 17, 2002 8:30 am - 11:00 am Room 5E-069 ATTENDEES John Gordon Robert Card Bruce Carnes Kathy Peery Brendan Danaher, AFGE Tony Lane Karen Evans Bill Sylvester Claudia Cross Brian Costlow Laurie Smith Helen Sherman Frank Bessera Rosalie Jordan Dennis O'Brien Mark Hively Robin Mudd Steven Apicella AGENDA 8:30 a.m. - 8:35 a.m. Opening Remarks 8:35a.m. - 8:55 a.m. Executive Steering Group roles and responsibilities, A-76 status, and talking points Team Briefings 8:55 a.m. - 9:20 a.m. Information Technology Study 9:20 a.m. - 9:45 a.m. Financial Services Study

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

FIELD RELIABILITY OF ELECTRONIC SYSTEMS  

E-Print Network [OSTI]

: ELECTRONIC EQUIPMENT; FAILURES; RELIABILITY; RISK ANALYSIS; SYSTEM ANALYSIS UDC: 621.38.004.64 ISBN 87 Predicted and Observed Reliability 16 3.3. Source 3 16 3.3.1. Description (Reactor Gamma Monitor) 16 3I Ww i 1 i FIELD RELIABILITY OF ELECTRONIC SYSTEMS wcwotoias R I S 0 - M - 2 4 1 8 An analytical

402

Advanced Photon Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Home Home Group Members Accelerator Magnets Insertion Devices Facilities Presentations & Publications Internal Magnetic Devices Group The primary mission of the Magnetic Devices (MD) Group is to design, build, and maintain Insertion Devices (IDs) that are reliable and transparent to the electron beam at the Advanced Photon Source (APS). The majority of IDs at the APS are conventional planar hybrid undulators, but an essential part of the mission is to develop novel IDs, such as short-period superconducting undulators and long-period electromagnetic undulators. The capabilities of APS IDs are matched to users' experimental needs. The mission also includes magnetic tuning of the IDs to ensure their near-ideal performance as x-ray sources and calculations to predict the radiation

403

Three chamber negative ion source  

DOE Patents [OSTI]

It is an object of this invention provide a negative ion source which efficiently provides a large flux of negatively ionized particles. This invention provides a volume source of negative ions which has a current density sufficient for magnetic fusion applications and has electrons suppressed from the output. It is still another object of this invention to provide a volume source of negative ions which can be electrostatically accelerated to high energies and subsequently neutralized to form a high energy neutral beam for use with a magnetically confined plasma.

Leung, K.N.; Ehlers, K.W.; Hiskes, J.R.

1983-11-10T23:59:59.000Z

404

IOP PUBLISHING PLASMA PHYSICS AND CONTROLLED FUSION Plasma Phys. Control. Fusion 51 (2009) 014008 (12pp) doi:10.1088/0741-3335/51/1/014008  

E-Print Network [OSTI]

(12pp) doi:10.1088/0741-3335/51/1/014008 Fast ignition of fusion targets by laser-driven electrons J J version) 1. Introduction Fast ignition [1, 2] involves transport of GA currents of laser-driven electrons. Results on actual ignition of an imploded fast ignition configuration are shown accounting

405

Are medical records a more reliable and valid source of CD4 count, viral load, and outpatient visit data than self-reports? A comparison with electronic medical records as the gold standard  

Science Journals Connector (OSTI)

CD4 cell count and viral load are the most widely used markers of ... abstracted paper medical record CD4 counts, viral load, and outpatient visits using electronic data as the gold standard. We sampled a ... con...

Janni J. Kinsler; William E. Cunningham…

2008-12-01T23:59:59.000Z

406

Long Plasma Source for Heavy Ion Beam Charge Neutralization  

E-Print Network [OSTI]

neutralizing plasma column the heavy ion beam can focus to aPlasmas are a source of unbound electrons for charge neutralizing intense heavy ion beams to focus

Efthimion, P.C.

2009-01-01T23:59:59.000Z

407

High intensity x-ray source using liquid gallium target  

DOE Patents [OSTI]

A high intensity x-ray source that uses a flowing stream of liquid gallium as a target with the electron beam impinging directly on the liquid metal.

Smither, Robert K. (Hinsdale, IL); Knapp, Gordon S. (Cupertino, CA); Westbrook, Edwin M. (Chicago, IL); Forster, George A. (Westmont, IL)

1990-01-01T23:59:59.000Z

408

COMPETITIVE SOURCING  

Broader source: Energy.gov (indexed) [DOE]

EXECUTIVE STEERING GROUP Meeting Proceedings October 30, 2002 Room 6E-069, 10:30 - 12:00 Agenda Opening Remarks Bruce Carnes Competitive Sourcing Update Denny O'Brien Team Briefings Team Leads ESG Discussion/Wrap up Bruce Carnes Attendees Bruce Carnes, Acting Chair MaryAnn Shebek Robert Card Prentis Cook Ambassador Brooks Tony Lane Kyle McSlarrow Karen Evans Suzanne Brennan, NTEU Claudia Cross Brian Costlow Helen Sherman Frank Bessera Laurie Morman Denny O'Brien Travis McCrory Bill Pearce Jeff Dowl Mark Hively Steven Apicella Robin Mudd Bruce Carnes chaired the meeting and began with welcoming NTEU to the meeting. In regard to the OMB's Balanced Scorecard, the Department has achieved a Green on progress and we are close to achieving a yellow on status.

409

Electron Transfer  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3 3 Pierre Kennepohl1,2 and Edward Solomon1* 1Department of Chemistry, Stanford University, Stanford, CA 94305 Electron transfer, or the act of moving an electron from one place to another, is amongst the simplest of chemical processes, yet certainly one of the most critical. The process of efficiently and controllably moving electrons around is one of the primary regulation mechanisms in biology. Without stringent control of electrons in living organisms, life could simply not exist. For example, photosynthesis and nitrogen fixation (to name but two of the most well-known biochemical activities) are driven by electron transfer processes. It is unsurprising, therefore, that much effort has been placed on understanding the fundamental principles that control and define the simple act of adding and/or removing electrons from chemical species.

410

E-Print Network 3.0 - auroral electron acceleration Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and vice versa. 4... of isolated auroral arcs. This means that upgoing electron beams (upward acceleration re- gions) can exist... electron ... Source: Ecole Polytechnique,...

411

E-Print Network 3.0 - auger electron emitting Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

high yield of Auger electrons originating from carbon surface atoms is observed... V intensity(arbitraryunits) electron energy (eV) ... Source: Groningen, Rijksuniversiteit -...

412

Electronic structure of superconductivity refined  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electronic structure of superconductivity refined Electronic structure of superconductivity refined Electronic structure of superconductivity refined A team of physicists propose a new model that expands on a little understood aspect of the electronic structure in high-temperature superconductors. July 10, 2008 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials.

413

Electronic imaging system and technique  

DOE Patents [OSTI]

A method and system for viewing objects obscurred by intense plasmas or flames (such as a welding arc) includes a pulsed light source to illuminate the object, the peak brightness of the light reflected from the object being greater than the brightness of the intense plasma or flame; an electronic image sensor for detecting a pulsed image of the illuminated object, the sensor being operated as a high-speed shutter; and electronic means for synchronizing the shutter operation with the pulsed light source.

Bolstad, Jon O. (Idaho Falls, ID)

1987-01-01T23:59:59.000Z

414

Polarized Electrons  

Science Journals Connector (OSTI)

Since 1972, when the last survey of Polarized Electrons was presented at an International Conference on Atomic Physics, the field has progressed to the point where it has entered a new phase, one which, I beli...

M. S. Lubell

1977-01-01T23:59:59.000Z

415

Electron Bernstein  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

, where pe 2 e 2 n e 0 m e is the plasma frequency and ce eBm e is the cyclotron frequency. However, the elec- trostatic electron Bernstein wave EBW does...

416

SNS | Spallation Neutron Source | ORNL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

SNS SNS Instruments Working with SNS Contact Us User Program Manager Laura Morris Edwards 865.574.2966 Spallation Neutron Source Home | User Facilities | SNS SNS | Spallation Neutron Source SHARE SNS is an accelerator-based neutron source in Oak Ridge, Tennessee, USA. This one-of-a-kind facility provides the most intense pulsed neutron beams in the world for scientific research and industrial development. The 80-acre SNS site is located on Chestnut Ridge and is part of Oak Ridge National Laboratory. Although most people don't know it, neutron scattering research has a lot to do with our everyday lives. For example, things like medicine, food, electronics, and cars and airplanes have all been improved by neutron scattering research. Neutron research also helps scientists improve materials used in a

417

Rippled beam free electron laser amplifier  

DOE Patents [OSTI]

A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a TM.sub.0n mode. A waveguide defines an axial centerline and, a solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.

Carlsten, Bruce E. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

418

An overview of LINAC ion sources  

SciTech Connect (OSTI)

This paper discusses ion sources used in high-duty-factor proton and H{sup -} Linacs as well as in accelerators utilizing multi-charged heavy ions, mostly for nuclear physics applications. The included types are Electron Cyclotron Resonance (ECR) sources as well as filament and rf driven multicusp sources. The paper does not strive to attain encyclopedic character but rather to highlight major lines of development, peak performance parameters and type-specific limitations and problems of these sources. The main technical aspects being discussed are particle feed, plasma generation and ion production by discharges, and plasma confinement.

Keller, Roderich [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

419

Tetrahydrothiophene 1-oxide as an electron acceptor for Escherichia coli.  

Science Journals Connector (OSTI)

...research-article Research Article Tetrahydrothiophene 1-oxide as an electron acceptor...Schrementi Escherichia coli used tetrahydrothiophene 1-oxide (THTO) as an electron...source; the THTO was reduced to tetrahydrothiophene. Cell extracts also reduced THTO...

R Meganathan; J Schrementi

1987-06-01T23:59:59.000Z

420

Use of gradient magnets in low emittance electron storage rings  

SciTech Connect (OSTI)

The use of gradient magnets for a low emittance electron storage ring is discussed and a magnetic lattice for a 6 GeV electron energy synchrotron radiation source adopting this feature is presented.

Vignola, G.

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Electron temperature of Titan's sunlit ionosphere M. Galand,1  

E-Print Network [OSTI]

Electron temperature of Titan's sunlit ionosphere M. Galand,1 R. V. Yelle,2 A. J. Coates,3 H spacecraft and assess the ionization and electron heating sources in Titan's sunlit ionosphere. We compare CAPS electron spectra with spectra produced by an electron transport model based on the INMS neutral

Yelle, Roger V.

422

E-Print Network 3.0 - anode front-end electronics Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Need cold cathodes: simplicity, efficiency, durability Best... ) electron beam Cathode Pulsed ... Source: Fusiongnition Research Experiment (FIRE) Collection: Plasma...

423

High-energy-resolution monochromator for aberration-corrected scanning transmission electron microscopy/electron energy-loss spectroscopy  

Science Journals Connector (OSTI)

...equal to the beam current per unit area per unit solid angle per unit energy interval, CFE electron sources with their...Monochromated, spatially resolved electron energy-loss spectroscopic measurements of gold nanoparticles in the plasmon range...

2009-01-01T23:59:59.000Z

424

Direct photoetching of polymers using radiation of high energy density from a table-top extreme ultraviolet plasma source  

Science Journals Connector (OSTI)

In order to perform material interaction studies with intense extreme ultraviolet(EUV)radiation a Schwarzschild mirror objective coated with Mo/Si multilayers was adapted to a compact laser-driven EUV plasma source utilizing a solid Au target. By 10× demagnified imaging of the plasma a maximum pulse energy density of ? 0.73 ? J / cm 2 at a wavelength of 13.5 nm can be achieved in the image plane of the objective at a pulse duration of 8.8 ns. In this paper we present EUV photoetching rates measured for polymethyl methacrylate polycarbonate and polytetrafluoroethylene at various fluence levels. A linear dependence between etch depth and applied EUV pulse number could be observed without the necessity for any incubation pulses. By evaluating the slope of these data etch rates were determined revealing also a linear behavior for low fluences. A threshold energy density could not be observed. The slope of the linear etch regime as well as deviations from the linear trend at higher energy densities are discussed and compared to data known from deep UV laser ablation. Furthermore the surface roughness of the structuredpolymers was measured by atomic force microscopy and compared to the nonirradiated polymer surface indicating a rather smooth etch process (roughness increase of 20%–30%). The different shapes of the etch craters observed for the three polymers at high energy densities can be explained by the measured fluence dependence of the etch rates having consequences for the proper use of polymerablation for beam profiling of focused EUVradiation.

Frank Barkusky; Armin Bayer; Christian Peth; Klaus Mann

2009-01-01T23:59:59.000Z

425

Direct photoetching of polymers using radiation of high energy density from a table-top extreme ultraviolet plasma source  

SciTech Connect (OSTI)

In order to perform material interaction studies with intense extreme ultraviolet (EUV) radiation, a Schwarzschild mirror objective coated with Mo/Si multilayers was adapted to a compact laser-driven EUV plasma source utilizing a solid Au target. By 10x demagnified imaging of the plasma a maximum pulse energy density of {approx}0.73 J/cm{sup 2} at a wavelength of 13.5 nm can be achieved in the image plane of the objective at a pulse duration of 8.8 ns. In this paper we present EUV photoetching rates measured for polymethyl methacrylate, polycarbonate, and polytetrafluoroethylene at various fluence levels. A linear dependence between etch depth and applied EUV pulse number could be observed without the necessity for any incubation pulses. By evaluating the slope of these data, etch rates were determined, revealing also a linear behavior for low fluences. A threshold energy density could not be observed. The slope of the linear etch regime as well as deviations from the linear trend at higher energy densities are discussed and compared to data known from deep UV laser ablation. Furthermore, the surface roughness of the structured polymers was measured by atomic force microscopy and compared to the nonirradiated polymer surface, indicating a rather smooth etch process (roughness increase of 20%-30%). The different shapes of the etch craters observed for the three polymers at high energy densities can be explained by the measured fluence dependence of the etch rates, having consequences for the proper use of polymer ablation for beam profiling of focused EUV radiation.

Barkusky, Frank; Bayer, Armin; Peth, Christian; Mann, Klaus [Laser-Laboratorium-Goettingen e.V., Hans-Adolf-Krebs-Weg 1, D-37077 Goettingen (Germany)

2009-01-01T23:59:59.000Z

426

ELECTRON COOLING FOR RHIC* Ilan Ben-Zvi  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

by the electron beam recombination is an additional source of losses. The value of radiative recombination coefficient req is given by the equation 2: ...

427

Varying Electron Cyclotron Resonance Heating on the Levitated Dipole Experiment  

Science Journals Connector (OSTI)

Plasmas in the Levitated Dipole Experiment (LDX) are formed and sustained currently via two electron cyclotron resonance heating (ECRH) sources: 2.5 kW at...

A. K. Hansen; A. C. Boxer; J. L. Ellsworth; D. T. Garnier…

2007-06-01T23:59:59.000Z

428

H- radio frequency source development at the Spallation Neutron Source  

SciTech Connect (OSTI)

The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent {approx}38 mA peak current in the linac and an availability of {approx}90%. H{sup -} beam pulses ({approx}1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, {approx}60 kW) of a copper antenna that has been encased with a thickness of {approx}0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of {approx}99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of {approx}75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance/installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to {approx}100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

Welton, Robert F [ORNL; Pennisi, Terry R [ORNL; Roseberry, Ron T [ORNL; Stockli, Martin P [ORNL

2012-01-01T23:59:59.000Z

429

Science Highlights 2007 | Advanced Photon Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Hybrid Semiconductors for Hardier Electronics and Optoelectronics? Hybrid Semiconductors for Hardier Electronics and Optoelectronics? Hybrid Semiconductors for Hardier Electronics and Optoelectronics? December 21, 2007 New research at the Advanced Photon Source has shed light on a semiconducting material with zero thermal expansion, and may play a role in the design of future generations of electronics and optoelectronics that can withstand a wide range of temperatures. Unveiling the Molecular Structure of the Target of Many Drugs Unveiling the Molecular Structure of the Target of Many Drugs December 3, 2007 More than 40 years after beta blockers were first used clinically, scientists using a beamline at the Advanced Photon Source finally got a close-up look at the drug's molecular target - the ß2-adrenergic receptor - research that promises to speed the discovery

430

Electron Impedances  

SciTech Connect (OSTI)

It is only recently, and particularly with the quantum Hall effect and the development of nanoelectronics, that impedances on the scale of molecules, atoms and single electrons have gained attention. In what follows the possibility that characteristic impedances might be defined for the photon and the single free electron is explored is some detail, the premise being that the concepts of electrical and mechanical impedances are relevant to the elementary particle. The scale invariant quantum Hall impedance is pivotal in this exploration, as is the two body problem and Mach's principle.

P Cameron

2011-12-31T23:59:59.000Z

431

Dispersion compensation for attosecond electron pulses  

SciTech Connect (OSTI)

We propose a device to compensate for the dispersion of attosecond electron pulses. The device uses only static electric and magnetic fields and therefore does not require synchronization to the pulsed electron source. Analogous to the well-known optical dispersion compensator, an electron dispersion compensator separates paths by energy in space. Magnetic fields are used as the dispersing element, while a Wien filter is used for compensation of the electron arrival times. We analyze a device with a size of centimeters, which can be applied to ultrafast electron diffraction and microscopy, and fundamental studies.

Hansen, Peter; Baumgarten, Cory; Batelaan, Herman; Centurion, Martin [Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States)

2012-08-20T23:59:59.000Z

432

Ultra-bright pulsed electron beam with low longitudinal emittance  

DOE Patents [OSTI]

A high-brightness pulsed electron source, which has the potential for many useful applications in electron microscopy, inverse photo-emission, low energy electron scattering experiments, and electron holography has been described. The source makes use of Cs atoms in an atomic beam. The source is cycled beginning with a laser pulse that excites a single Cs atom on average to a band of high-lying Rydberg nP states. The resulting valence electron Rydberg wave packet evolves in a nearly classical Kepler orbit. When the electron reaches apogee, an electric field pulse is applied that ionizes the atom and accelerates the electron away from its parent ion. The collection of electron wave packets thus generated in a series of cycles can occupy a phase volume near the quantum limit and it can possess very high brightness. Each wave packet can exhibit a considerable degree of coherence.

Zolotorev, Max (Oakland, CA)

2010-07-13T23:59:59.000Z

433

Capital Sources and Providers  

Broader source: Energy.gov [DOE]

The most important elements of a clean energy lending program are the capital source and the capital provider. The capital source provides the funding to pay for clean energy projects, and the capital provider manages those funding sources. For example, a bank might use its customers' deposits as a capital source, but as the capital provider, the bank manages the investment of that capital.

434

Laser-driven, magnetized quasi-perpendicular collisionless shocks on the Large Plasma Devicea)  

E-Print Network [OSTI]

and Astronomy, University of California - Los Angeles, Los Angeles, California 90095, USA 2 Los Alamos National Plasma Device [Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)] at the University of California, Los environments, including supernovae remnants, coronal mass ejections, the solar wind, and iono- spheric

California at Los Angles, University of

435

Ultrathin Polymer Films for Short-Pulse Laser-Driven Proton, Deuteron, and Carbon Ion Beams  

Science Journals Connector (OSTI)

Technical Paper / Selected papers from 20th Target Fabrication Meeting, May 20-24, 2012, Santa Fe, NM, Guest Editor: Robert C. Cook

Christopher E. Hamilton; Nickolaus A. Smith; Kimberly A. Defriend Obrey

436

Single shot ultrafast dynamic ellipsometry (UDE) of laser-driven shocks in single crystal explosives  

SciTech Connect (OSTI)

We report on the first experiments to measure states in shocked energetic single crystals with dynamic ellipsometry. We demonstrate that these ellipsometric techniques can produce reasonable Hugoniot values using small amounts of crystalline RDX and PETN. Pressures, particle velocities and shock velocities obtained using shocked ellipsometry are comparable to those found using gas-gun flyer plates and molecular dynamics calculations. The adaptation of the technique from uniform thin films of polymers to thick non-perfect crystalline materials was a significant achievement. Correct sample preparation proved to be a crucial component. Through trial and error, we were able to resolve polishing issues, sample quality problems, birefringence effects and mounting difficulties that were not encountered using thin polymer films.

Whitley, Von H [Los Alamos National Laboratory; Mcgrane, Shawn D [Los Alamos National Laboratory; Moore, David S [Los Alamos National Laboratory; Eakins, Dan E [Los Alamos National Laboratory; Bolme, Cindy A [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

437

Laser-driven shock experiments on precompressed water: Implications for "icy" giant planets  

E-Print Network [OSTI]

, California 94720- 4767 and Department of Physics, New Mexico State University, MSC 3D, Las Cruces, New Mexico Solar Sys- tem, are expected to be common among extrasolar planets, and can reveal important information- rents generated by a dynamo. Although some of the magne- tism in our Solar System can be attributed

Lee, Kanani K. M.

438

A threshold for laser-driven linear particle acceleration in unbounded vacuum  

E-Print Network [OSTI]

We hypothesize that a charged particle in unbounded vacuum can be substantially accelerated by a force linear in the electric field of a propagating electromagnetic wave only if the accelerating field is capable of bringing ...

Wong, Liang Jie

2011-01-01T23:59:59.000Z

439

Quantification of Uncertainties Due to Opacities in a Laser-Driven Radiative-Shock Problem  

E-Print Network [OSTI]

......................................................................... 44 3.2 Introduction to Uncertain Parameters in Opacity Calculations ......................... 45 3.3 Analysis of Relevant Uncertain Data Used in the CRASH Code ..................... 45 3.3.1 Evaluation of Oscillator Strengths... with Adjusted Xenon Opacity .......... 71 5.1.3 Results Using Oscillator Strengths ............................................................ 80 5.1.4 Results Using Oscillator Strengths with Adjusted Xenon Opacity ........... 89 5.2 Results for the 1-D...

Hetzler, Adam C

2013-03-28T23:59:59.000Z

440

Laser-driven hole boring and gamma-ray emission in high-density plasmas  

E-Print Network [OSTI]

Ion acceleration in laser-produced dense plasmas is a key topic of many recent investigations thanks to its potential applications. Besides, at forthcoming laser intensities ($I \\gtrsim 10^{23} \\text{W}\\,\\text{cm}^{-2}$) interaction of laser pulses with plasmas can be accompanied by copious gamma-ray emission. Here we demonstrate the mutual influence of gamma-ray emission and ion acceleration during relativistic hole boring in high-density plasmas with ultra-intense laser pulses. If gamma-ray emission is abundant, laser pulse reflection and hole-boring velocity are lower and gamma-ray radiation pattern is narrower than in the case of low emission. Conservation of energy and momentum allows one to elucidate the effects of gamma-ray emission which are more pronounced at higher hole-boring velocities.

Nerush, Evgeny

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

First time nuclear material detection by one short-pulse-laser-driven neutron  

E-Print Network [OSTI]

counters; one detector containing a 2 kg sample of depleted uranium, and the other one empty for background comparison. A single shot interrogation of the depleted uranium sample, showed a clear signal from the delayed neutrons in the detector with uranium, compared with the background, and with the typical time

Kurien, Susan

442

Radiation transport and energetics of laser-driven half-hohlraums at the National Ignition Facility  

SciTech Connect (OSTI)

Experiments that characterize and develop a high energy-density half-hohlraum platform for use in benchmarking radiation hydrodynamics models have been conducted at the National Ignition Facility (NIF). Results from the experiments are used to quantitatively compare with simulations of the radiation transported through an evolving plasma density structure, colloquially known as an N-wave. A half-hohlraum is heated by 80 NIF beams to a temperature of 240?eV. This creates a subsonic diffusive Marshak wave, which propagates into a high atomic number Ta{sub 2}O{sub 5} aerogel. The subsequent radiation transport through the aerogel and through slots cut into the aerogel layer is investigated. We describe a set of experiments that test the hohlraum performance and report on a range of x-ray measurements that absolutely quantify the energetics and radiation partition inside the target.

Moore, A. S., E-mail: alastair.moore@physics.org; Graham, P.; Comley, A. J.; Foster, J. [Directorate Science and Technology, AWE Aldermaston, Reading RG7 4PR (United Kingdom); Cooper, A. B. R.; Schneider, M. B.; MacLaren, S.; Lu, K.; Seugling, R.; Satcher, J.; Klingmann, J.; Marrs, R.; May, M.; Widmann, K.; Glendinning, G.; Castor, J.; Sain, J.; Baker, K.; Hsing, W. W.; Young, B. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); and others

2014-06-15T23:59:59.000Z

443

Laser-driven search of axion-like particles including vacuum polarization effects  

E-Print Network [OSTI]

Oscillations of photons into axion-like particles in a high-intensity laser field are investigated. Nonlinear QED effects are considered through the low energy behavior of the vacuum polarization tensor, which is derived from the Euler-Heisenberg Lagrangian in the one-loop and weak field approximations. The expressions obtained in this framework are applied to the configuration in which the strong background field is a circularly polarized monochromatic plane wave. The outcomes of this analysis reveal that, in the regime of low energy-momentum transfer, the axion field induces a chiral-like birefringence and dichroism in the vacuum which is not manifest in a pure QED context. The corresponding ellipticity and angular rotation of the polarization plane are also determined. We take advantage of such observables to impose exclusion limits on the axion parameters. Our predictions cover axion masses for which a setup based on dipole magnets provides less stringent constraints. Possible experimental scenarios in which our results could be tested are also discussed.

Selym Villalba-Chávez

2014-02-26T23:59:59.000Z

444

Laser-driven nanoplasmas in doped helium droplets: Local ignition and anisotropic expansion  

E-Print Network [OSTI]

Doping a helium nanodroplet with a tiny xenon cluster of a few atoms only, sparks complete ionization of the droplet at laser intensities below the ionization threshold of helium atoms. As a result, the intrinsically inert and transparent droplet turns into a fast and strong absorber of infrared light. Microscopic calculations reveal a two-step mechanism to be responsible for the dramatic change: Avalanche-like ionization of the helium atoms on a femtosecond time scale, driven by field ionization due to the quickly charged xenon core is followed by resonant absorption enabled by an unusual cigar-shaped nanoplasma within the droplet.

Mikaberidze, Alexey; Rost, Jan M

2009-01-01T23:59:59.000Z

445

Laser-Driven Nanoplasmas in Doped Helium Droplets: Local Ignition and Anisotropic Growth  

Science Journals Connector (OSTI)

Doping a helium nanodroplet with only a tiny xenon cluster of a few atoms sparks complete ionization of the droplet at laser intensities below the ionization threshold of helium atoms. As a result, the intrinsically inert and transparent droplet turns into a fast and strong absorber of infrared light. Microscopic calculations reveal a two-step mechanism to be responsible for the dramatic change: Avalanchelike ionization of the helium atoms on a femtosecond time scale, driven by field ionization due to the quickly charged xenon core, is followed by resonant absorption enabled by an unusual cigar-shaped nanoplasma within the droplet.

Alexey Mikaberidze, Ulf Saalmann, and Jan M. Rost

2009-03-25T23:59:59.000Z

446

High-intensity laser-driven proton acceleration: influence of pulse contrast  

Science Journals Connector (OSTI)

...inset of figure 3. CR-39 nuclear track detector, which is...pump down cycle of the target vacuum chamber. The proton stopping...hadrontherapy with laser ion accelerators. Phys. Lett. A. 299...laser virtual-cathode plasma accelerator. Phys. Rev. Lett. 92...

2006-01-01T23:59:59.000Z

447

Instability, mixing, and transition to turbulence in a laser-driven counterflowing shear experiment  

SciTech Connect (OSTI)

In a turbulence experiment conducted at the Omega Laser Facility [Boehly et al., Opt. Commun. 133, 495 (1997)

Doss, F. W.; Loomis, E. N.; Welser-Sherrill, L.; Fincke, J. R.; Flippo, K. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Keiter, P. A. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2013-01-15T23:59:59.000Z

448

GEOMETRIC SOURCE SEPARATION: MERGING CONVOLUTIVE SOURCE  

E-Print Network [OSTI]

adaptive beamforming algorithms by a cross-power criteria, we gain new geometric source separation with convo- lutive blind source separation. We concentrate on cross-power spectral min- imization which is su to ambiguities in the choice of separating lters. There are in theory multiple lters that invert the room

Parra, Lucas C.

449

Electron CoolingElectron Cooling Sergei Nagaitsev  

E-Print Network [OSTI]

Electron CoolingElectron Cooling Sergei Nagaitsev FNAL - AD April 28, 2005 #12;Electron Cooling methods must "get around the theorem" e.g. by pushing phase-space around. #12;Electron Cooling - Nagaitsev 3 TodayToday''s Menus Menu What is cooling? Types of beam cooling Electron cooling Conclusions #12

Fermilab

450

Conversion Electrons of Radium D  

Science Journals Connector (OSTI)

The conversion electrons of radium D have been studied with thin sources on thin backings in a beta-ray spectrograph using calibrated photographic emulsions. The number of conversion electrons due to the 47-kev gamma-ray has been measured to be 74±5 per hundred disintegrations. The L:M:N ratio is 1:0.26:0.077. This implies a complex decay scheme for radium D, since earlier results give 3.5 unconverted 47-kev gamma-rays per hundred disintegrations.

Lawrence Cranberg

1950-01-15T23:59:59.000Z

451

National Synchrotron Light Source II Project Progress Report  

E-Print Network [OSTI]

, power supply procurement, BPM electronics testing, and controls system design. With details of technical'S ASSESSMENT FEBRUARY 2010 OVERALL ASSESSMENT The National Synchrotron Light Source II project maintained excellent technical progress and satisfactory cost and schedule performance. The DOE Independent Project

Ohta, Shigemi

452

ccsd00001953, A comparative analysis of the electron energy  

E-Print Network [OSTI]

-1027, 11801 M#19;exico D. F., MEXICO E-mail: cgt@nuclear.inin.mx Abstract. To establish the electron energyccsd­00001953, version 1 ­ 22 Oct 2004 A comparative analysis of the electron energy distribution place in ECR plasma sources, where low pressure plasma is sustained by electron impact ionization

453

Transmission Electron Microscope and Scanning Electron Microscopes -  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Facilities > Transmission Electron Facilities > Transmission Electron Microscope and Scanning Electron Microscopes FACILITIES Transmission Electron Microscope and Scanning Electron Microscopes Overview Other Facilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Transmission Electron Microscope and Scanning Electron Microscopes The research activities of the Corrosion and Mechanics of Materials Section are supported by complete metallography/sample preparation rooms equipped with several optical and electron microscopes: a Transmission Electron Microscope and two Scanning Electron Microscopes. Bookmark and Share Transmission electron microscope (TEM) Detail of JEOL 100CXII TEM Figure 1: Detail of JEOL 100CXII TEM. Click on image to view larger image.

454

Coherence of k-space electrons: application to TDS electrons by DBI  

Science Journals Connector (OSTI)

......Special Issue: Tribute to Akira Tonomura Coherence of k-space electrons: application...The results presented show the partial coherence of self-interfered diffusely scattered...electron source of a TEM have sufficient coherence to form fringes when self-interfered......

Rodney A. Herring

2013-06-01T23:59:59.000Z

455

NREL: Advanced Power Electronics - Publications  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Publications Publications The National Renewable Energy Laboratory and its partners have produced many papers and presentations related to the Advanced Power Electronics project. For more information about the following documents, contact Sreekant Narumanchi. Software Spray System Evaluation (Software 1.1 MB) Papers 2013 Steady and Unsteady Air Impingement Heat Transfer for Electronics Cooling Applications Paper Source: Arik, M.; Sharma, R.; Lustbader, J.; He, X. (2013). Article No. 111009. Journal of Heat Transfer. Vol. 135(11), November 2013; 8 pp.; NREL Report No. JA-5400-56618. http://dx.doi.org/10.1115/1.4024614 Pool Boiling Heat Transfer Characteristics of HFO-1234yf on Plain and Microporous-Enhanced Surfaces Paper Source: Moreno, G.; Narumanchi, S.; King, C. (2013). Article No. 111014.

456

Unraveling resistive versus collisional contributions to relativistic electron beam stopping power in cold-solid and in warm-dense plasmas  

SciTech Connect (OSTI)

We present results on laser-driven relativistic electron beam propagation through aluminum samples, which are either solid and cold or compressed and heated by laser-induced shock. A full numerical description of fast electron generation and transport is found to reproduce the experimental absolute K{sub ?} yield and spot size measurements for varying target thicknesses, and to sequentially quantify the collisional and resistive electron stopping powers. The results demonstrate that both stopping mechanisms are enhanced in compressed Al samples and are attributed to the increase in the medium density and resistivity, respectively. For the achieved time- and space-averaged electronic current density, ?j{sub h}??8×10{sup 10}?A/cm{sup 2} in the samples, the collisional and resistive stopping powers in warm and compressed Al are estimated to be 1.5?keV/?m and 0.8?keV/?m, respectively. By contrast, for cold and solid Al, the corresponding estimated values are 1.1?keV/?m and 0.6?keV/?m. Prospective numerical simulations involving higher j{sub h} show that the resistive stopping power can reach the same level as the collisional one. In addition to the effects of compression, the effect of the transient behavior of the resistivity of Al during relativistic electron beam transport becomes progressively more dominant, and for a significantly high current density, j{sub h}?10{sup 12}?A/cm{sup 2}, cancels the difference in the electron resistive stopping power (or the total stopping power in units of areal density) between solid and compressed samples. Analytical calculations extend the analysis up to j{sub h}=10{sup 14}?A/cm{sup 2} (representative of the full-scale fast ignition scenario of inertial confinement fusion), where a very rapid transition to the Spitzer resistivity regime saturates the resistive stopping power, averaged over the electron beam duration, to values of ?1?keV/?m.

Vauzour, B. [CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), Univ. Bordeaux, UMR 5107, F-33405 Talence (France) [CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), Univ. Bordeaux, UMR 5107, F-33405 Talence (France); Laboratoire d'Optique Appliquée, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France); Debayle, A. [ETSI Aeronáuticos, Universidad Politécnica de Madrid, Madrid (Spain) [ETSI Aeronáuticos, Universidad Politécnica de Madrid, Madrid (Spain); CEA, DAM, DIF, F-91297 Arpajon (France); Vaisseau, X.; Hulin, S.; Nicolaï, Ph.; Dorchies, F.; Fourment, C.; D'Humières, E.; Tikhonchuk, V. T.; Santos, J. J., E-mail: santos.joao@celia.u-bordeaux1.fr [CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), Univ. Bordeaux, UMR 5107, F-33405 Talence (France); Schlenvoigt, H.-P.; Baton, S. D.; Yahia, V. [LULI, Ecole Polytechnique, CNRS/CEA/UPMC, 91128 Palaiseau Cedex (France)] [LULI, Ecole Polytechnique, CNRS/CEA/UPMC, 91128 Palaiseau Cedex (France); Batani, D. [CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), Univ. Bordeaux, UMR 5107, F-33405 Talence (France) [CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), Univ. Bordeaux, UMR 5107, F-33405 Talence (France); Dipartimento di Fisica, Università di Milano-Bicocca, Milano 20126 (Italy); Honrubia, J. J. [ETSI Aeronáuticos, Universidad Politécnica de Madrid, Madrid (Spain)] [ETSI Aeronáuticos, Universidad Politécnica de Madrid, Madrid (Spain); Beg, F. N.; Chawla, S.; Jarrot, L. C. [University of California, San Diego, La Jolla, California 92093 (United States)] [University of California, San Diego, La Jolla, California 92093 (United States); Benocci, R.; Volpe, L. [Dipartimento di Fisica, Università di Milano-Bicocca, Milano 20126 (Italy)] [Dipartimento di Fisica, Università di Milano-Bicocca, Milano 20126 (Italy); and others

2014-03-15T23:59:59.000Z

457

Photo-stimulated low electron temperature high current diamond film field emission cathode  

DOE Patents [OSTI]

An electron source includes a back contact surface having a means for attaching a power source to the back contact surface. The electron source also includes a layer comprising platinum in direct contact with the back contact surface, a composite layer of single-walled carbon nanotubes embedded in platinum in direct contact with the layer comprising platinum. The electron source also includes a nanocrystalline diamond layer in direct contact with the composite layer. The nanocrystalline diamond layer is doped with boron. A portion of the back contact surface is removed to reveal the underlying platinum. The electron source is contained in an evacuable container.

Shurter; Roger Philips (Los Alamos, NM), Devlin; David James (Santa Fe, NM), Moody; Nathan Andrew (Los Alamos, NM), Taccetti; Jose Martin (Santa Fe, NM), Russell; Steven John (Los Alamos, NM)

2012-07-24T23:59:59.000Z

458

A power supply unit for discharging the plasma electron source  

Science Journals Connector (OSTI)

A power supply unit for discharging a low-temperature plasma generator based on discharge in the crossed electric and magnetic fields is described. The unit operates in a stationary mode with a preset stabiliz...

D. A. Antonovich; V. A. Gruzdev; V. G. Zalesskii…

459

Los Alamos: MST: MST-6: EML: Electron Microscopy Laboratory  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Strata DB235 FIB/SEM (Focused Ion Beam/High Reolution Scanning Electron Microscope) Strata DB235 FIB/SEM (Focused Ion Beam/High Reolution Scanning Electron Microscope) FEI Strata DB235 FIB/SEM (Focused Ion Beam/High Reolution Scanning Electron Microscope) This is a versatile field emission scanning electron microscope integrated with a focused ion beam column that is used for sophisticated SEM and TEM sample preparation, micromachining, and ultrahigh resolution SEM imaging. The microscope is also equipped for x-ray microanalysis and crystallographic orientation imaging. Microscope consists of a Hexalens SFEG electron beam column, and a Magnum ion beam column with a gallium liquid metal ion source. Imaging with both secondary electrons and ions. Digital image acquisition. Small, stable, high brightness Schottky based field emission electron source provides 1.5 nm resolution at 30 kV. Three electron beam lens modes - normal imaging, high resolution imaging, and EDS imaging.

460

Laser-PlasmaWakefield Acceleration with Higher Order Laser Modes  

E-Print Network [OSTI]

Design considerations for a laser-plasma linear collider,"E.Esarey, and W.P.Leemans, "Free-electron laser driven bythe LBNL laser-plasma accelerator," in Proc. Adv. Acc. Con.

Geddes, C.G.R.

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

E-Print Network 3.0 - acceleration measurement system Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

30043. Summary: -stage energy gain and the maximum acceleration distance versus the laser crossing angle, subject to the system... for a laser-driven electron accelerator Y.C....

462

Note on RF Photo-Cathode Gun  

E-Print Network [OSTI]

Emittances in Laser-Driven RF Guns", Proc. 1988 Linear Acc.Palmer, "Preliminary Study of Gun Emittance Correction", BNLLaser-Driven RF Electron Guns", Nuc1. ln stt. Meth. , A275,

Kim, Kwang-Je

2010-01-01T23:59:59.000Z

463

E-Print Network 3.0 - alpha tagged x-ray Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

-X-ray pinhole camera -Fast electron beam spatial distribution 5m... ? Fusion Energy Fast Ignition Optimisation high power laser-driven ion -Cu K-alpha imaging system -X-ray... and...

464

Hybrid simulation of electron cyclotron resonance heating  

Science Journals Connector (OSTI)

Electron Cyclotron Resonance (ECR) heating is a fundamentally important aspect in understanding the physics of Electron Cyclotron Resonance Ion Sources (ECRIS). Absorption of the radio frequency (RF) microwave power by electron heating in the resonance zone depends on many parameters including frequency and electric field strength of the microwave, magnetic field structure and electron and ion density profiles. ECR absorption has been studied in the past by e.g. modelling electric field behaviour in the resonance zone and its near proximity. This paper introduces a new ECR heating code that implements damping of the microwave power in the vicinity of the resonance zone, utilizes electron density profiles and uses right hand circularly polarized (RHCP) electromagnetic waves to simulate electron heating in ECRIS plasma.

T. Ropponen; O. Tarvainen; P. Suominen; T.K. Koponen; T. Kalvas; H. Koivisto

2008-01-01T23:59:59.000Z

465

Ion-induced electron emission microscopy  

DOE Patents [OSTI]

An ion beam analysis system that creates multidimensional maps of the effects of high energy ions from an unfocussed source upon a sample by correlating the exact entry point of an ion into a sample by projection imaging of the secondary electrons emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted secondary electrons are collected in a strong electric field perpendicular to the sample surface and (optionally) projected and refocused by the electron lenses found in a photon emission electron microscope, amplified by microchannel plates and then their exact position is sensed by a very sensitive X Y position detector. Position signals from this secondary electron detector are then correlated in time with nuclear, atomic or electrical effects, including the malfunction of digital circuits, detected within the sample that were caused by the individual ion that created these secondary electrons in the fit place.

Doyle, Barney L. (Albuquerque, NM); Vizkelethy, Gyorgy (Albuquerque, NM); Weller, Robert A. (Brentwood, TN)

2001-01-01T23:59:59.000Z

466

Particle acceleration in double radio sources  

Science Journals Connector (OSTI)

Further study has been made of a model of extragalactic double radio sources in which the magnetized accretion disc of a massive black hole acts as an electric dynamo producing oppositely directed beams of relativistic particles. An empty region of small angular size—a vortice core—is shown to be a possible consequence of the hydrodynamics of accretion of gas with angular momentum. An ambient magnetic field in the gas tends to accumulate in the core region. The acceleration of electrons in the dynamo electric field gives rise to oppositely directed electron beams which in turn produce synchroton gamma rays collimated along the core. Collisions between the gamma rays and low energy photons caN initiate an electromagnetic cascade shower. The cascade acts to produce a collimated relativistic electron?positron beam. If the current flow in the dynamo occurs in surges then the outward propagation of the head of the electron–positron beams may produce expanding compact radio components. The electron–positron beam is ballistic in nature and it is electrically neutral and carries no current. Such a beam appears to have favorable stability properties. The beam is eventually stopped and spread out in pitch angle by the ram pressure of the external medium. Synchrotron radiated lobes of double radio sources.

R. V. E. Lovelace; J. MacAuslan; M. Burns

1979-01-01T23:59:59.000Z

467

Compton backscattered collimated x-ray source  

DOE Patents [OSTI]

A high-intensity, inexpensive and collimated x-ray source is disclosed for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications. 4 figs.

Ruth, R.D.; Huang, Z.

1998-10-20T23:59:59.000Z

468

Compton backscattered collmated X-ray source  

DOE Patents [OSTI]

A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)

2000-01-01T23:59:59.000Z

469

Compton backscattered collimated x-ray source  

DOE Patents [OSTI]

A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)

1998-01-01T23:59:59.000Z

470

TrakLok Corporation | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Integrated Dynamic Electron Solutions, Inc. Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic Transmission Electron Microscopes (DTEM) to enable imaging of nanoscale objects, such as proteins, thin films and nanoparticles at unprecedented time scales and frame rates. By utilizing a laser-driven electron source, DTEMs are able to produce short bursts of electrons that can form an image with nanometer resolution in as little as 10 nanoseconds. This enables observation of dynamics in material systems that play an important role in a wide range of energy technologies, including battery electrodes, petroleum catalysts, solar cell materials, and organisms for bio fuel growth. Integrated Dynamic Electron Solutions uses technology

471

Iowa Powder Atomization Technologies, Inc. | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Integrated Dynamic Electron Solutions, Inc. Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic Transmission Electron Microscopes (DTEM) to enable imaging of nanoscale objects, such as proteins, thin films and nanoparticles at unprecedented time scales and frame rates. By utilizing a laser-driven electron source, DTEMs are able to produce short bursts of electrons that can form an image with nanometer resolution in as little as 10 nanoseconds. This enables observation of dynamics in material systems that play an important role in a wide range of energy technologies, including battery electrodes, petroleum catalysts, solar cell materials, and organisms for bio fuel growth. Integrated Dynamic Electron Solutions uses technology

472

SH Coatings LP | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Integrated Dynamic Electron Solutions, Inc. Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic Transmission Electron Microscopes (DTEM) to enable imaging of nanoscale objects, such as proteins, thin films and nanoparticles at unprecedented time scales and frame rates. By utilizing a laser-driven electron source, DTEMs are able to produce short bursts of electrons that can form an image with nanometer resolution in as little as 10 nanoseconds. This enables observation of dynamics in material systems that play an important role in a wide range of energy technologies, including battery electrodes, petroleum catalysts, solar cell materials, and organisms for bio fuel growth. Integrated Dynamic Electron Solutions uses technology

473

Umpqua Energy, Inc. | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Integrated Dynamic Electron Solutions, Inc. Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic Transmission Electron Microscopes (DTEM) to enable imaging of nanoscale objects, such as proteins, thin films and nanoparticles at unprecedented time scales and frame rates. By utilizing a laser-driven electron source, DTEMs are able to produce short bursts of electrons that can form an image with nanometer resolution in as little as 10 nanoseconds. This enables observation of dynamics in material systems that play an important role in a wide range of energy technologies, including battery electrodes, petroleum catalysts, solar cell materials, and organisms for bio fuel growth. Integrated Dynamic Electron Solutions uses technology

474

California Lithium Battery, Inc. | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Integrated Dynamic Electron Solutions, Inc. Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic Transmission Electron Microscopes (DTEM) to enable imaging of nanoscale objects, such as proteins, thin films and nanoparticles at unprecedented time scales and frame rates. By utilizing a laser-driven electron source, DTEMs are able to produce short bursts of electrons that can form an image with nanometer resolution in as little as 10 nanoseconds. This enables observation of dynamics in material systems that play an important role in a wide range of energy technologies, including battery electrodes, petroleum catalysts, solar cell materials, and organisms for bio fuel growth. Integrated Dynamic Electron Solutions uses technology

475

Vorbeck Materials Corp. | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Integrated Dynamic Electron Solutions, Inc. Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic Transmission Electron Microscopes (DTEM) to enable imaging of nanoscale objects, such as proteins, thin films and nanoparticles at unprecedented time scales and frame rates. By utilizing a laser-driven electron source, DTEMs are able to produce short bursts of electrons that can form an image with nanometer resolution in as little as 10 nanoseconds. This enables observation of dynamics in material systems that play an important role in a wide range of energy technologies, including battery electrodes, petroleum catalysts, solar cell materials, and organisms for bio fuel growth. Integrated Dynamic Electron Solutions uses technology

476

SynchroPET LLC | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Integrated Dynamic Electron Solutions, Inc. Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic Transmission Electron Microscopes (DTEM) to enable imaging of nanoscale objects, such as proteins, thin films and nanoparticles at unprecedented time scales and frame rates. By utilizing a laser-driven electron source, DTEMs are able to produce short bursts of electrons that can form an image with nanometer resolution in as little as 10 nanoseconds. This enables observation of dynamics in material systems that play an important role in a wide range of energy technologies, including battery electrodes, petroleum catalysts, solar cell materials, and organisms for bio fuel growth. Integrated Dynamic Electron Solutions uses technology

477

Teknikem, A Division of RockinBoat LLC | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Integrated Dynamic Electron Solutions, Inc. Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic Transmission Electron Microscopes (DTEM) to enable imaging of nanoscale objects, such as proteins, thin films and nanoparticles at unprecedented time scales and frame rates. By utilizing a laser-driven electron source, DTEMs are able to produce short bursts of electrons that can form an image with nanometer resolution in as little as 10 nanoseconds. This enables observation of dynamics in material systems that play an important role in a wide range of energy technologies, including battery electrodes, petroleum catalysts, solar cell materials, and organisms for bio fuel growth. Integrated Dynamic Electron Solutions uses technology

478

Element One, Inc. | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Integrated Dynamic Electron Solutions, Inc. Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic Transmission Electron Microscopes (DTEM) to enable imaging of nanoscale objects, such as proteins, thin films and nanoparticles at unprecedented time scales and frame rates. By utilizing a laser-driven electron source, DTEMs are able to produce short bursts of electrons that can form an image with nanometer resolution in as little as 10 nanoseconds. This enables observation of dynamics in material systems that play an important role in a wide range of energy technologies, including battery electrodes, petroleum catalysts, solar cell materials, and organisms for bio fuel growth. Integrated Dynamic Electron Solutions uses technology

479

America's Next Top Energy Innovator Challenge | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Integrated Dynamic Electron Solutions, Inc. Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic Transmission Electron Microscopes (DTEM) to enable imaging of nanoscale objects, such as proteins, thin films and nanoparticles at unprecedented time scales and frame rates. By utilizing a laser-driven electron source, DTEMs are able to produce short bursts of electrons that can form an image with nanometer resolution in as little as 10 nanoseconds. This enables observation of dynamics in material systems that play an important role in a wide range of energy technologies, including battery electrodes, petroleum catalysts, solar cell materials, and organisms for bio fuel growth. Integrated Dynamic Electron Solutions uses technology

480

Calibration of a DSSSD detector with radioactive sources  

SciTech Connect (OSTI)

The energy calibration of a DSSSD is carried out with the spectra produced by a {sup 207}Bi conversion electron source, a {sup 137}Cs gamma source and a {sup 239}Pu/{sup 241}Am/{sup 244}Cm triple alpha source, as well as employing a precision pulse generator in the whole dynamic range. Multiplicity and coincidence of signals in different strips for the same event are also studied.

Guadilla, V.; Tain, J. L.; Agramunt, J.; Algora, A.; Domingo-Pardo, C.; Rubio, B. [Instituto de Fisica Corpuscular, C.S.I.C.-Univ. Valencia, Ap 22085, E-46071, Valencia (Spain)

2013-06-10T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Spallation Neutron Source, SNS  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Spallation Neutron Source Spallation Neutron Source Providing the most intense pulsed neutron beams in the world... Accumulator Ring Commissioning Latest Step for Spallation Neutron Source The Spallation Neutron Source, located at Oak Ridge National Laboratory, has passed another milestone on the way to completion this year--the commissioning of the proton accumulator ring. Brookhaven led the design and construction of the accumulator ring, which will allow an order of magnitude more beam power than any other facility in the world. The Spallation Neutron Source (SNS) is an accelerator-based neutron source being built in Oak Ridge, Tennessee, by the U.S. Department of Energy. The figure on the right shows a schematic of the accumulator ring and transport beam lines that are being designed and built by Brookhaven

482

High intensity line source for x-ray spectrometer calibration  

SciTech Connect (OSTI)

A high intensity electron-impact x-ray source using a one-dimensional Pierce lens has been built for the purpose of calibrating a bent crystal x-ray spectrometer. This source focuses up to 100 mA of 20-keV electrons to a line on a liquid-cooled anode. The line (which can serve as a virtual slit for the spectrometer) measures approximately 800 ..mu.. x 2 cm. The source is portable and therefore adaptable to numerous types of spectrometer applications. One particular application, the calibration of a high resolution (r = 10/sup 4/) time-resolved cyrstal spectrometer, will be discussed in detail.

Thoe, R.S.

1986-06-01T23:59:59.000Z

483

Light sources based on semiconductor current filaments  

DOE Patents [OSTI]

The present invention provides a new type of semiconductor light source that can produce a high peak power output and is not injection, e-beam, or optically pumped. The present invention is capable of producing high quality coherent or incoherent optical emission. The present invention is based on current filaments, unlike conventional semiconductor lasers that are based on p-n junctions. The present invention provides a light source formed by an electron-hole plasma inside a current filament. The electron-hole plasma can be several hundred microns in diameter and several centimeters long. A current filament can be initiated optically or with an e-beam, but can be pumped electrically across a large insulating region. A current filament can be produced in high gain photoconductive semiconductor switches. The light source provided by the present invention has a potentially large volume and therefore a potentially large energy per pulse or peak power available from a single (coherent) semiconductor laser. Like other semiconductor lasers, these light sources will emit radiation at the wavelength near the bandgap energy (for GaAs 875 nm or near infra red). Immediate potential applications of the present invention include high energy, short pulse, compact, low cost lasers and other incoherent light sources.

Zutavern, Fred J. (Albuquerque, NM); Loubriel, Guillermo M. (Albuquerque, NM); Buttram, Malcolm T. (Sandia Park, NM); Mar, Alan (Albuquerque, NM); Helgeson, Wesley D. (Albuquerque, NM); O'Malley, Martin W. (Edgewood, NM); Hjalmarson, Harold P. (Albuquerque, NM); Baca, Albert G. (Albuquerque, NM); Chow, Weng W. (Cedar Crest, NM); Vawter, G. Allen (Albuquerque, NM)

2003-01-01T23:59:59.000Z

484

Sources and Electrodynamics  

Science Journals Connector (OSTI)

A new kind of particle theory is being explored, one that is intermediate in concept between the extremes of S matrix and field theory. It employs the methods of neither approach. There are no operators, and there is no appeal to analyticity in momentum space. It is a phenomenological theory, and cognizant that measurements are operations in space and time. Particles are defined realistically by reference to their creation or annihilation in suitable collisions. The source is introduced as an abstraction of the role played by all the other particles involved in such acts. Through the use of sources the production and detection of particles, as well as their interaction, are incorporated into the theoretical description. There is a creative principle that replaces the devices of other formulations. It is an insistence upon the generality of the space-time description of the coupling among sources that is inferred from a specific spatio-temporal arrangement, in which various particles propagate between sources. Standard quantum-mechanical and relativistic requirements, imposed on the source description of noninteracting particles, imply the existence of the two statistics and the connection with spin. In this situation sources are only required to emit and absorb the mass of the corresponding particle. Particle dynamics is introduced by an extension of the source concept. It is considered meaningful for a source to emit several particles with the same total quantum numbers as a single particle, if sufficient mass is available. This is most familiar as the photon radiation that accompanies the emission of charged particles. The new types of sources introduced in this way imply new couplings among sources, which supply still further varieties of sources. This proliferation of interactions spans the full dynamical content of the initial primitive interaction. The ambition of the phenomenological source theory is to represent all dynamical aspects of particles, within a certain context, by a suitable primitive interaction. This paper is devoted to the reconstruction of electrodynamics.

Julian Schwinger

1967-06-25T23:59:59.000Z

485

Publications | Advanced Photon Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

research at the APS. It is the official source for listing APS-related journal articles, conference proceedings and papers, dissertations, books, book chapters, technical reports,...

486

NGLS: Next Generation Light Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Lab masthead Berkeley Lab A-Z Index Phone Book Careers Search DOE logo Lab masthead Berkeley Lab A-Z Index Phone Book Careers Search DOE logo NGLS logo NGLS Science NGLS Technology Seminars Workshop/Reports Related Links Further Info NGLS Facility Combustion Photosynthesis Photosynthesis Photosynthesis Today is a golden age for light sources. Storage ring-based synchrotrons routinely provide X-ray beams exploited by thousands of scientists annually to answer fundamental questions in diverse fields including human health, energy, and electronics and information processing. MORE > NGLS Science Science section chart NGLS CD-0 Proposal NGLS Technology Technology section chart Seminars Science section chart Workshops Science section chart Last updated 06/21/2013 Top A U.S. Department of Energy National Laboratory Operated by the University

487

Radiation Source Replacement Workshop  

SciTech Connect (OSTI)

This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

2010-12-01T23:59:59.000Z

488

source | OpenEI  

Open Energy Info (EERE)

source source Dataset Summary Description This dataset comes from the Energy Information Administration (EIA), and is part of the 2011 Annual Energy Outlook Report (AEO2011). This dataset is table 17, and contains only the reference case. The dataset uses quadrillion Btu. The data is broken down into marketed renewable energy, residential, commercial, industrial, transportation and electric power. Source EIA Date Released April 26th, 2011 (3 years ago) Date Updated Unknown Keywords Commercial Electric Power Industrial Renewable Energy Consumption Residential sector source transportation Data application/vnd.ms-excel icon AEO2011: Renewable Energy Consumption by Sector and Source- Reference Case (xls, 105 KiB) Quality Metrics Level of Review Peer Reviewed Comment

489

Neutron sources and applications  

SciTech Connect (OSTI)

Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications.

Price, D.L. [ed.] [Argonne National Lab., IL (United States); Rush, J.J. [ed.] [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

1994-01-01T23:59:59.000Z

490

Glossary Term - Electron Capture  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electron Electron Previous Term (Electron) Glossary Main Index Next Term (Electron Volt (eV)) Electron Volt (eV) Electron Capture After electron capture, an atom contains one less proton and one more neutron. Electron capture is one process that unstable atoms can use to become more stable. During electron capture, an electron in an atom's inner shell is drawn into the nucleus where it combines with a proton, forming a neutron and a neutrino. The neutrino is ejected from the atom's nucleus. Since an atom loses a proton during electron capture, it changes from one element to another. For example, after undergoing electron capture, an atom of carbon (with 6 protons) becomes an atom of boron (with 5 protons). Although the numbers of protons and neutrons in an atom's nucleus change

491

Volumetric plasma source development and characterization.  

SciTech Connect (OSTI)

The development of plasma sources with densities and temperatures in the 10{sup 15}-10{sup 17} cm{sup -3} and 1-10eV ranges which are slowly varying over several hundreds of nanoseconds within several cubic centimeter volumes is of interest for applications such as intense electron beam focusing as part of the x-ray radiography program. In particular, theoretical work [1,2] suggests that replacing neutral gas in electron beam focusing cells with highly conductive, pre-ionized plasma increases the time-averaged e-beam intensity on target, resulting in brighter x-ray sources. This LDRD project was an attempt to generate such a plasma source from fine metal wires. A high voltage (20-60kV), high current (12-45kA) capacitive discharge was sent through a 100 {micro}m diameter aluminum wire forming a plasma. The plasma's expansion was measured in time and space using spectroscopic techniques. Lineshapes and intensities from various plasma species were used to determine electron and ion densities and temperatures. Electron densities from the mid-10{sup 15} to mid-10{sup 16} cm{sup -3} were generated with corresponding electron temperatures of between 1 and 10eV. These parameters were measured at distances of up to 1.85 cm from the wire surface at times in excess of 1 {micro}s from the initial wire breakdown event. In addition, a hydrocarbon plasma from surface contaminants on the wire was also measured. Control of these contaminants by judicious choice of wire material, size, and/or surface coating allows for the ability to generate plasmas with similar density and temperature to those given above, but with lower atomic masses.

Crain, Marlon D. (National Security Technologies, LLC, Las Vegas, NV); Maron, Yitzhak (Weizmann Institute of Science, Rehovot, Israel); Oliver, Bryan Velten; Starbird, Robert L. (National Security Technologies, LLC, Las Vegas, NV); Johnston, Mark D.; Hahn, Kelly Denise; Mehlhorn, Thomas Alan; Droemer, Darryl W. (National Security Technologies, LLC, Las Vegas, NV); National Security Technologies, LLC, Las Vegas, NV

2008-09-01T23:59:59.000Z

492

5 - Surface Wave Plasma Sources  

Science Journals Connector (OSTI)

Publisher Summary This chapter summarizes the advantages of the surface wave (SW) plasma sources. It includes a summary of the wave and plasma properties of SW sustained plasma columns, review of the essential parts composing a SW plasma source; describes a family of efficient SW launchers for such plasma sources, dwells on three typical experimental arrangements and a brief summary recalling the advantages of SW plasma sources. Surface wave discharges have the advantage of the broadest operating conditions in terms of frequency, tube dimensions and shape, and gas pressure. For example they can be utilized over both the RF (radiofrequency) and microwave domains, which permits one to optimize given processes as a function of frequency (generally through changes in the electron energy distribution function). A further advantage of SW plasmas is that they are the best modeled HF plasmas. This provides insight into HF discharges in general since, to a first approximation, the local plasma properties of SW discharges are the same as in all RF and microwave discharges under given discharge conditions, and for a given HF power density deposited in the plasma. Compared to other RF and microwave plasma sources, SW discharges are undoubtedly the most flexible ones. They also are efficient discharges since very little HF power is lost in the impedance matching circuit. Finally, a major future avenue for these discharges is their operation as magnetized plasmas. As a first approach to presenting surface wave (SW) plasma sources, let us consider their distinctive features with respect to the other plasma sources described in the book:o1. The discharge can be sustained far away from the active zone of the field applicator. This is because the electric field supporting the discharge is provided by a wave that carries away the power from the applicator. It is an electromagnetic surface wave whose sole guiding structure is the plasma column that it sustains and the dielectric tube enclosing it [1]–[3]. This is, thus, a non-cumbersome method for producing long plasma columns; plasma columns up to 6 meters in length have been achieved in our laboratory while launching the wave with a field applicator that surrounded the discharge tube over a few centimeters in length only. [4][5] 2. The range of the applied field frequency f=?/2? is the broadest of all kinds of high frequency (HF) sustained plasma sources. We have succeeded in realizing HF power transfer to the discharge efficiently from approximately 10 \\{MHz\\} to 10 \\{GHz\\} [6] and, with impaired coupling efficiency, down to 200 kHz [7]. This frequency range includes radiofrequencies (RF) and the lower part of the microwave frequency spectrum; we use the term high frequencies to designate RF as well as microwave frequencies. An interesting aspect of this frequency flexibility is the possibility of acting on the electron energy distribution function (EEDF) to optimize a given plasma process [8]. 3. The gas pressure range is extremely large. On the one hand, one can operate SW discharges in the sub-mtorr range under electron cyclotron resonance (ECR) conditions, [9] while, on the other hand, it is possible to sustain a stable plasma of a few millimeters diameter at pressures at least a few times atmospheric pressure [10]. 4. The range of plasma, density, n, is very large. At reduced pressure and with f in the few \\{MHz\\} range, n, can be as low as 108 cm?3, [7] while at atmospheric pressure it can exceed 1015 cm?3[10] A related parameter is the degree of ionization ?i, i.e. the plasma density relative to the initial neutral atom concentration. Under ECR conditions, for example with f=2.45 \\{GHz\\} where n can reach up to a few 1012 cm?3, ?i ranges approximately from 0.1–10%, whereas in the above-mentioned atmospheric pressure case, it is smaller than 10?4. The higher n, the higher the rate of plasma processes depending on ions or on neutral particles (e.g., atoms, radicals) when the latter are obtained through electron collisions [8]. Large ?i values favor the existence of

Michel Moisan; Joëlle Margot; Zenon Zakrzewski

1996-01-01T23:59:59.000Z

493

Ponderomotive phase plate for transmission electron microscopes  

DOE Patents [OSTI]

A ponderomotive phase plate system and method for controllably producing highly tunable phase contrast transfer functions in a transmission electron microscope (TEM) for high resolution and biological phase contrast imaging. The system and method includes a laser source and a beam transport system to produce a focused laser crossover as a phase plate, so that a ponderomotive potential of the focused laser crossover produces a scattering-angle-dependent phase shift in the electrons of the post-sample electron beam corresponding to a desired phase contrast transfer function.

Reed, Bryan W. (Livermore, CA)

2012-07-10T23:59:59.000Z

494

Controlling Graphene's Electronic Structure  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Controlling Graphene's Electronic Structure Print Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has enormous potential for use in...

495

Controlling Graphene's Electronic Structure  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Controlling Graphene's Electronic Structure Print Wednesday, 25 April 2007 00:00 Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has...

496

Diamondoids Improve Electron Emitters  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

is unique to diamondoid, is believed to enable the development of a new generation of electron emitters with unprecedented properties. In Photoemission Electron Microscopy...

497

Radiative polarization of electrons  

Science Journals Connector (OSTI)

We present a new method of calculating the radiative polarization of electrons in homogeneous magnetic fields, using the modified electron propagation function.

Julian Schwinger and Wu-yang Tsai

1974-03-15T23:59:59.000Z

498

Light-Source Facilities  

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Facility, P.R. China CANDLE, Armenia HSRC - Hiroshima Synchrotron Radiation Center, Japan iFEL - Institute of Free Electron Laser, Japan INDUS 1 INDUS 2, India IR FEL...

499

The `excess' of primary cosmic ray electrons  

E-Print Network [OSTI]

With the accurate cosmic ray (CR) electron and positron spectra (denoted as $\\Phi_{\\rm e^{-}}$ and $\\Phi_{\\rm e^{+}}$, respectively) measured by AMS-02 collaboration, the difference between the electron and positron fluxes (i.e., $\\Delta \\Phi=\\Phi_{\\rm e^{-}}-\\Phi_{\\rm e^{+}}$), dominated by the propagated primary electrons, can be reliably inferred. In the standard model, the spectrum of propagated primary CR electrons at energies $\\geq 30$ GeV softens with the increase of energy. The absence of any evidence for such a continuous spectral softening in $\\Delta \\Phi$ strongly suggests a significant `excess' of primar